Why eyewitnesses get it wrong
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0:02 - 0:07The murder happened a little over 21 years ago,
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0:07 - 0:11January the 18th, 1991,
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0:11 - 0:13in a small
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0:13 - 0:15bedroom community
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0:15 - 0:18of Lynwood, California, just a few miles
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0:18 - 0:21southeast of Los Angeles.
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0:21 - 0:24A father came out of his house
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0:24 - 0:27to tell his teenage son and his five friends
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0:27 - 0:30that it was time for them to stop horsing around
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0:30 - 0:33on the front lawn and on the sidewalk,
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0:33 - 0:36to get home, finish their schoolwork,
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0:36 - 0:38and prepare themselves for bed.
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0:38 - 0:42And as the father was administering these instructions,
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0:42 - 0:45a car drove by, slowly,
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0:45 - 0:48and just after it passed the father and the teenagers,
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0:48 - 0:52a hand went out from the front passenger window,
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0:52 - 0:57and -- "Bam, Bam!" -- killing the father.
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0:57 - 1:01And the car sped off.
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1:01 - 1:02The police,
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1:02 - 1:06investigating officers, were amazingly efficient.
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1:06 - 1:09They considered all the usual culprits,
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1:09 - 1:13and in less than 24 hours, they had selected their suspect:
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1:13 - 1:17Francisco Carrillo, a 17-year-old kid
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1:17 - 1:19who lived about two or three blocks away
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1:19 - 1:22from where the shooting occurred.
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1:22 - 1:26They found photos of him. They prepared a photo array,
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1:26 - 1:30and the day after the shooting,
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1:30 - 1:33they showed it to one of the teenagers, and he said,
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1:33 - 1:35"That's the picture.
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1:35 - 1:40That's the shooter I saw that killed the father."
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1:40 - 1:43That was all a preliminary hearing judge had
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1:43 - 1:48to listen to, to bind Mr. Carrillo over to stand trial
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1:48 - 1:51for a first-degree murder.
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1:51 - 1:54In the investigation that followed before the actual trial,
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1:54 - 1:57each of the other five teenagers was shown
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1:57 - 2:02photographs, the same photo array.
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2:02 - 2:04The picture that we best can determine was probably
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2:04 - 2:07the one that they were shown in the photo array
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2:07 - 2:10is in your bottom left hand corner of these mug shots.
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2:10 - 2:14The reason we're not sure absolutely is because
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2:14 - 2:18of the nature of evidence preservation
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2:18 - 2:20in our judicial system,
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2:20 - 2:25but that's another whole TEDx talk for later. (Laughter)
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2:25 - 2:28So at the actual trial,
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2:28 - 2:31all six of the teenagers testified,
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2:31 - 2:35and indicated the identifications they had made
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2:35 - 2:38in the photo array.
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2:38 - 2:43He was convicted. He was sentenced to life imprisonment,
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2:43 - 2:49and transported to Folsom Prison.
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2:49 - 2:51So what's wrong?
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2:51 - 2:55Straightforward, fair trial, full investigation.
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2:55 - 2:59Oh yes, no gun was ever found.
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2:59 - 3:03No vehicle was ever identified as being the one
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3:03 - 3:06in which the shooter had extended his arm,
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3:06 - 3:10and no person was ever charged with being the driver
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3:10 - 3:13of the shooter's vehicle.
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3:13 - 3:17And Mr. Carrillo's alibi?
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3:17 - 3:22Which of those parents here in the room might not lie
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3:22 - 3:25concerning the whereabouts of your son or daughter
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3:25 - 3:29in an investigation of a killing?
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3:31 - 3:34Sent to prison,
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3:34 - 3:37adamantly insisting on his innocence,
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3:37 - 3:42which he has consistently for 21 years.
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3:42 - 3:45So what's the problem?
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3:45 - 3:48The problems, actually, for this kind of case
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3:48 - 3:52come manyfold from decades of scientific research
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3:52 - 3:56involving human memory.
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3:56 - 3:59First of all, we have all the statistical analyses
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3:59 - 4:01from the Innocence Project work,
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4:01 - 4:04where we know that we have, what,
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4:04 - 4:07250, 280 documented cases now where people have
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4:07 - 4:11been wrongfully convicted and subsequently exonerated,
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4:11 - 4:18some from death row, on the basis of later DNA analysis,
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4:18 - 4:21and you know that over three quarters of all of those cases
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4:21 - 4:28of exoneration involved only eyewitness identification
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4:28 - 4:31testimony during the trial that convicted them.
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4:31 - 4:37We know that eyewitness identifications are fallible.
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4:37 - 4:39The other comes from an interesting aspect
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4:39 - 4:42of human memory that's related to various brain functions
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4:42 - 4:44but I can sum up for the sake of brevity here
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4:44 - 4:47in a simple line:
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4:47 - 4:52The brain abhors a vacuum.
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4:52 - 4:56Under the best of observation conditions,
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4:56 - 4:57the absolute best,
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4:57 - 5:01we only detect, encode and store in our brains
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5:01 - 5:05bits and pieces of the entire experience in front of us,
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5:05 - 5:07and they're stored in different parts of the brain.
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5:07 - 5:11So now, when it's important for us to be able to recall
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5:11 - 5:14what it was that we experienced,
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5:14 - 5:20we have an incomplete, we have a partial store,
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5:20 - 5:22and what happens?
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5:22 - 5:25Below awareness, with no requirement for any kind of
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5:25 - 5:30motivated processing, the brain fills in information
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5:30 - 5:32that was not there,
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5:32 - 5:35not originally stored,
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5:35 - 5:37from inference, from speculation,
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5:37 - 5:40from sources of information that came to you,
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5:40 - 5:43as the observer, after the observation.
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5:43 - 5:45But it happens without awareness such that
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5:45 - 5:49you don't, aren't even cognizant of it occurring.
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5:49 - 5:51It's called reconstructed memories.
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5:51 - 5:58It happens to us in all the aspects of our life, all the time.
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5:58 - 6:02Let me ask you to consider the horrific events of 9/11.
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6:02 - 6:05Think about when you first got the information
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6:05 - 6:09about this catastrophe, how you felt,
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6:09 - 6:12and more importantly,
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6:12 - 6:18when was the first time you saw the second trade tower
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6:18 - 6:20implode and collapse
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6:20 - 6:24after the first trade tower had gone down?
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6:24 - 6:27If you're like most Americans, myself included,
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6:27 - 6:30you have a very clear memory that you saw the first tower
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6:30 - 6:33come down and then you saw the second tower
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6:33 - 6:37finally collapse, after the other plane crashed into it,
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6:37 - 6:40within an hour or two afterwards.
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6:40 - 6:41I remember vividly where I was.
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6:41 - 6:44I was down at LAX at the satellite terminal
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6:44 - 6:46for American Airlines
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6:46 - 6:48waiting to get on an airplanes to fly to San Diego,
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6:48 - 6:51and of course all the air traffic was ceased.
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6:51 - 6:53And so I had nothing to do but to sit and watch
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6:53 - 6:55the television monitors with all of the news broadcasts
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6:55 - 6:58over and over and over again
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6:58 - 7:02of the horrendous events.
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7:02 - 7:06And I know I saw that second trade tower come down
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7:06 - 7:10an hour or two after the first.
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7:10 - 7:12And all of the research we have indicates that
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7:12 - 7:15most Americans too, except for a few people who happen
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7:15 - 7:18to live in certain places in New York, right?
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7:18 - 7:20And you know something?
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7:20 - 7:23That's a totally false memory.
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7:23 - 7:26It could not be something you experienced.
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7:26 - 7:29There was absolutely no media footage
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7:29 - 7:31of the second trade tower collapsing
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7:31 - 7:36until over 24 hours after the event.
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7:36 - 7:41But in fact, you know, intellectually, cognitively,
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7:41 - 7:44that they did occur fairly close in time,
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7:44 - 7:47you did know about and see the first one,
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7:47 - 7:49you did see the second one,
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7:49 - 7:53but you didn't see it until over a day later at the earliest,
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7:53 - 7:56but the brain, without you being aware,
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7:56 - 7:58has pulled them together,
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7:58 - 8:02and you believe you saw them very close in time.
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8:02 - 8:04It is a reconstructed memory,
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8:04 - 8:07not an accurate memory,
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8:07 - 8:10no matter how vivid, no matter how sure you are.
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8:10 - 8:13It was those two considerations among others,
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8:13 - 8:14reconstructive memories,
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8:14 - 8:17the fact about the eyewitness fallibility,
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8:17 - 8:20that was part of the instigation
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8:20 - 8:23for a group of appeal attorneys
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8:23 - 8:26led by an amazing lawyer named Ellen Eggers
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8:26 - 8:30to pool their experience and their talents together
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8:30 - 8:33and petition a superior court
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8:33 - 8:37for a retrial for Francisco Carrillo.
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8:37 - 8:41They retained me, as a forensic neurophysiologist,
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8:41 - 8:44because I had expertise
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8:44 - 8:46in eyewitness memory identification,
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8:46 - 8:49which obviously makes sense for this case, right?
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8:49 - 8:52But also because I have expertise and testify about
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8:52 - 8:57the nature of human night vision.
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8:57 - 9:00Well, what's that got to do with this?
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9:00 - 9:03Well, when you read through the case materials
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9:03 - 9:06in this Carrillo case,
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9:06 - 9:08one of the things that suddenly strikes you is that
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9:08 - 9:12the investigating officers said the lighting was good
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9:12 - 9:15at the crime scene, at the shooting.
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9:15 - 9:19All the teenagers testified during the trial
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9:19 - 9:22that they could see very well.
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9:22 - 9:25But this occurred in mid-January,
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9:25 - 9:32in the Northern Hemisphere, at 7 p.m. at night.
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9:32 - 9:34So when I did the calculations
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9:34 - 9:37for the lunar data and the solar data
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9:37 - 9:40at that location on Earth at the time of the incident
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9:40 - 9:42of the shooting, all right,
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9:42 - 9:44it was well past the end of civil twilight
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9:44 - 9:47and there was no moon up that night.
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9:47 - 9:49So all the light in this area from the sun and the moon
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9:49 - 9:52is what you see on the screen right here.
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9:52 - 9:55The only lighting in that area had to come
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9:55 - 9:58from artificial sources,
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9:58 - 10:00and that's where I go out and I do the actual reconstruction
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10:00 - 10:03of the scene with photometers, with various measures
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10:03 - 10:06of illumination and various other measures of
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10:06 - 10:09color perception, along with special cameras
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10:09 - 10:12and high speed film, right?
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10:12 - 10:15Take all the measurements and record them, right?
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10:15 - 10:17And then take photographs, and this is what the scene
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10:17 - 10:19looked like at the time of the shooting
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10:19 - 10:22from the position of the teenagers
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10:22 - 10:24looking at the car going by and shooting.
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10:24 - 10:27This is looking directly across the street
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10:27 - 10:29from where they were standing.
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10:29 - 10:32Remember, the investigating officers' report said
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10:32 - 10:34the lighting was good.
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10:34 - 10:36The teenagers said they could see very well.
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10:36 - 10:40This is looking down to the east,
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10:40 - 10:43where the shooting vehicle sped off,
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10:45 - 10:48and this is the lighting directly behind the father
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10:48 - 10:51and the teenagers.
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10:51 - 10:54As you can see, it is at best poor.
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10:54 - 10:58No one's going to call this well-lit, good lighting,
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10:58 - 11:02and in fact, as nice as these pictures are,
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11:02 - 11:05and the reason we take them is I knew I was going to have to testify in court,
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11:05 - 11:08and a picture is worth more than a thousand words
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11:08 - 11:10when you're trying to communicate numbers,
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11:10 - 11:13abstract concepts like lux, the international measurement
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11:13 - 11:20of illumination, the Ishihara color perception test values.
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11:20 - 11:22When you present those to people who are not well-versed
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11:22 - 11:25in those aspects of science and that, they become
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11:25 - 11:28salamanders in the noonday sun. It's like
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11:28 - 11:31talking about the tangent of the visual angle, all right?
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11:31 - 11:33Their eyes just glaze over, all right?
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11:33 - 11:37A good forensic expert also has to be a good educator,
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11:37 - 11:40a good communicator, and that's part of the reason
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11:40 - 11:43why we take the pictures, to show not only
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11:43 - 11:45where the light sources are, and what we call the spill,
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11:45 - 11:48the distribution, but also so that it's easier
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11:48 - 11:52for the trier of fact to understand the circumstances.
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11:52 - 11:55So these are some of the pictures that, in fact,
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11:55 - 11:57I used when I testified,
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11:57 - 11:59but more importantly were, to me as a scientist,
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11:59 - 12:01are those readings, the photometer readings,
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12:01 - 12:05which I can then convert into actual predictions
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12:05 - 12:09of the visual capability of the human eye
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12:09 - 12:11under those circumstances,
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12:11 - 12:15and from my readings that I recorded at the scene
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12:15 - 12:17under the same solar and lunar conditions
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12:17 - 12:20at the same time, so on and so forth, right,
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12:20 - 12:22I could predict
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12:22 - 12:24that there would be no reliable color perception,
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12:24 - 12:26which is crucial for face recognition,
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12:26 - 12:29and that there would be only scotopic vision,
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12:29 - 12:31which means there would be very little resolution,
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12:31 - 12:33what we call boundary or edge detection,
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12:33 - 12:35and that furthermore, because the eyes would have been
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12:35 - 12:39totally dilated under this light, the depth of field,
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12:39 - 12:42the distance at which you can focus and see details,
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12:42 - 12:48would have been less than 18 inches away.
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12:48 - 12:50I testified to that to the court,
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12:50 - 12:52and while the judge was very attentive,
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12:52 - 12:55it had been a very, very long hearing
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12:55 - 13:00for this petition for a retrial, and as a result,
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13:00 - 13:02I noticed out of the corner of my eye
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13:02 - 13:05that I thought that maybe the judge was going to need
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13:05 - 13:08a little more of a nudge
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13:08 - 13:10than just more numbers.
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13:10 - 13:12And here I became a bit audacious,
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13:12 - 13:14and I turned
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13:14 - 13:17and I asked the judge,
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13:17 - 13:19I said, "Your Honor, I think you should go out
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13:19 - 13:21and look at the scene yourself."
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13:21 - 13:24Now I may have used a tone which was more like a dare
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13:24 - 13:27than a request — (Laughter) —
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13:27 - 13:32but nonetheless, it's to this man's credit and his courage
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13:32 - 13:35that he said, "Yes, I will."
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13:35 - 13:39A shocker in American jurisprudence.
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13:39 - 13:41So in fact, we found the same identical conditions,
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13:41 - 13:44we reconstructed the entire thing again,
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13:44 - 13:47he came out with an entire brigade of sheriff's officers
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13:47 - 13:55to protect him in this community, all right? (Laughter)
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13:55 - 13:58We had him stand actually slightly in the street,
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13:58 - 14:01so closer to the suspect vehicle, the shooter vehicle,
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14:01 - 14:03than the actual teenagers were,
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14:03 - 14:06so he stood a few feet from the curb
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14:06 - 14:09toward the middle of the street.
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14:09 - 14:12We had a car that came by,
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14:12 - 14:16same identical car as described by the teenagers, right?
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14:16 - 14:18It had a driver and a passenger,
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14:18 - 14:22and after the car had passed the judge by,
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14:22 - 14:25the passenger extended his hand,
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14:25 - 14:30pointed it back to the judge as the car continued on,
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14:30 - 14:32just as the teenagers had described it, right?
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14:32 - 14:35Now, he didn't use a real gun in his hand,
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14:35 - 14:38so he had a black object in his hand that was similar
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14:38 - 14:40to the gun that was described.
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14:40 - 14:43He pointed by, and this is what the judge saw.
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14:43 - 14:50This is the car 30 feet away from the judge.
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14:50 - 14:52There's an arm sticking out of the passenger side
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14:52 - 14:55and pointed back at you.
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14:55 - 14:57That's 30 feet away.
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14:57 - 14:59Some of the teenagers said that in fact the car
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14:59 - 15:01was 15 feet away when it shot.
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15:01 - 15:06Okay. There's 15 feet.
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15:06 - 15:09At this point, I became a little concerned.
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15:09 - 15:15This judge is someone you'd never want to play poker with.
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15:15 - 15:18He was totally stoic. I couldn't see a twitch of his eyebrow.
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15:18 - 15:21I couldn't see the slightest bend of his head.
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15:21 - 15:25I had no sense of how he was reacting to this,
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15:25 - 15:28and after he looked at this reenactment,
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15:28 - 15:29he turned to me and he says,
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15:29 - 15:32"Is there anything else you want me to look at?"
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15:32 - 15:33(Laughter)
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15:33 - 15:37I said, "Your honor," and I don't know whether I was
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15:37 - 15:40emboldened by the scientific measurements that I had
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15:40 - 15:44in my pocket and my knowledge that they are accurate,
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15:44 - 15:46or whether it was just sheer stupidity,
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15:46 - 15:49which is what the defense lawyers thought — (Laughter) —
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15:49 - 15:51when they heard me say,
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15:51 - 15:53"Yes, Your Honor, I want you stand right there
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15:53 - 15:57and I want the car to go around the block again
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15:57 - 16:01and I want it to come and I want it to stop
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16:01 - 16:05right in front of you, three to four feet away,
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16:05 - 16:08and I want the passenger to extend his hand
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16:08 - 16:11with a black object and point it right at you,
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16:11 - 16:16and you can look at it as long as you want."
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16:16 - 16:22And that's what he saw. (Laughter)
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16:22 - 16:25You'll notice, which was also in my test report,
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16:25 - 16:27all the dominant lighting is coming from the north side,
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16:27 - 16:29which means that the shooter's face would
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16:29 - 16:31have been photo-occluded. It would have been backlit.
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16:31 - 16:34Furthermore, the roof of the car
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16:34 - 16:38is causing what we call a shadow cloud inside the car
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16:38 - 16:41which is making it darker.
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16:41 - 16:47And this is three to four feet away.
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16:47 - 16:48Why did I take the risk?
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16:48 - 16:52I knew that the depth of field was 18 inches or less.
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16:52 - 16:55Three to four feet, it might as well have been
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16:55 - 16:58a football field away.
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16:59 - 17:01This is what he saw.
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17:01 - 17:05He went back, there was a few more days of evidence
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17:05 - 17:08that was heard. At the end of it,
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17:08 - 17:10he made the judgment that he was going to grant
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17:10 - 17:12the petition for a retrial.
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17:12 - 17:16And furthermore, he released Mr. Carrillo
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17:16 - 17:18so that he could aid in the preparation of his own defense
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17:18 - 17:25if the prosecution decided to retry him.
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17:25 - 17:27Which they decided not to.
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17:27 - 17:31He is now a freed man. (Applause)
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17:31 - 17:35(Applause)
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17:35 - 17:40This is him embracing his grandmother-in-law.
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17:40 - 17:45He -- His girlfriend was pregnant when he went to trial,
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17:45 - 17:48right? And she had a little baby boy.
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17:48 - 17:52He and his son are both attending Cal State Long Beach
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17:52 - 17:55right now taking classes. (Applause)
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17:55 - 17:58(Applause)
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17:58 - 18:02And what does this example --
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18:02 - 18:07what's important to keep in mind for ourselves?
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18:07 - 18:09First of all, there's a long history of antipathy
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18:09 - 18:12between science and the law
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18:12 - 18:14in American jurisprudence.
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18:14 - 18:18I could regale you with horror stories of ignorance
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18:18 - 18:22over decades of experience as a forensic expert
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18:22 - 18:26of just trying to get science into the courtroom.
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18:26 - 18:31The opposing council always fight it and oppose it.
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18:31 - 18:35One suggestion is that all of us become much more
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18:35 - 18:38attuned to the necessity, through policy,
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18:38 - 18:41through procedures,
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18:41 - 18:43to get more science in the courtroom,
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18:43 - 18:45and I think one large step toward that
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18:45 - 18:47is more requirements,
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18:47 - 18:50with all due respect to the law schools,
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18:50 - 18:55of science, technology, engineering, mathematics
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18:55 - 18:56for anyone going into the law,
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18:56 - 18:59because they become the judges.
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18:59 - 19:03Think about how we select our judges in this country.
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19:03 - 19:07It's very different than most other cultures. All right?
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19:07 - 19:09The other one that I want to suggest,
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19:09 - 19:11the caution that all of us have to have,
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19:11 - 19:14I constantly have to remind myself,
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19:14 - 19:16about just how accurate are the memories
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19:16 - 19:23that we know are true, that we believe in?
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19:23 - 19:26There is decades of research,
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19:26 - 19:30examples and examples of cases like this,
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19:30 - 19:32where individuals
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19:32 - 19:35really, really believe. None of those teenagers
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19:35 - 19:37who identified him
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19:37 - 19:40thought that they were picking the wrong person.
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19:40 - 19:43None of them thought they couldn't see the person's face.
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19:43 - 19:46We all have to be very careful.
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19:46 - 19:49All our memories are reconstructed memories.
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19:49 - 19:52They are the product of what we originally experienced
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19:52 - 19:54and everything that's happened afterwards.
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19:54 - 19:57They're dynamic.
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19:57 - 19:59They're malleable. They're volatile,
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19:59 - 20:04and as a result, we all need to remember to be cautious,
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20:04 - 20:06that the accuracy of our memories
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20:06 - 20:11is not measured in how vivid they are
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20:11 - 20:15nor how certain you are that they're correct.
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20:15 - 20:18I'm sure I saw the second trade tower collapse
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20:18 - 20:21an hour later,
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20:21 - 20:26but I know it could not have happened.
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20:26 - 20:30Thank you. (Applause)
- Title:
- Why eyewitnesses get it wrong
- Speaker:
- Scott Fraser
- Description:
-
Scott Fraser studies how humans remember crimes -- and bear witness to them. In this powerful talk, which focuses on a deadly shooting at sunset, he suggests that even close-up eyewitnesses to a crime can create "memories" they could not have seen. Why? Because the brain abhors a vacuum.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TEDTalks
- Duration:
- 20:50
Morton Bast edited English subtitles for Why eyewitnesses get it wrong | ||
Morton Bast edited English subtitles for Why eyewitnesses get it wrong | ||
Meryl Ducray edited English subtitles for Why eyewitnesses get it wrong | ||
Gruia Diana edited English subtitles for Why eyewitnesses get it wrong | ||
Morton Bast edited English subtitles for Why eyewitnesses get it wrong | ||
Thu-Huong Ha approved English subtitles for Why eyewitnesses get it wrong | ||
Morton Bast accepted English subtitles for Why eyewitnesses get it wrong | ||
Morton Bast edited English subtitles for Why eyewitnesses get it wrong |