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 - 5:56It happens to us in all the aspects of our life, all the time.
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5:56 - 5:59It was those two considerations, among others --
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5:59 - 6:03reconstructed memory, the fact about the eyewitness fallibility --
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6:03 - 6:07that was part of the instigation
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6:07 - 6:09for a group of appeal attorneys
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6:09 - 6:12led by an amazing lawyer named Ellen Eggers
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6:12 - 6:17to pool their experience and their talents together
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6:17 - 6:18and petition a superior court
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6:18 - 6:23for a retrial for Francisco Carrillo.
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6:23 - 6:28They retained me, as a forensic neurophysiologist,
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6:28 - 6:30because I had expertise
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6:30 - 6:32in eyewitness memory identification,
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6:32 - 6:35which obviously makes sense for this case, right?
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6:35 - 6:39But also because I have expertise and testify about
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6:39 - 6:43the nature of human night vision.
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6:43 - 6:46Well, what's that got to do with this?
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6:46 - 6:49Well, when you read through the case materials
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6:49 - 6:52in this Carrillo case,
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6:52 - 6:55one of the things that suddenly strikes you is that
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6:55 - 6:58the investigating officers said the lighting was good
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6:58 - 7:02at the crime scene, at the shooting.
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7:02 - 7:05All the teenagers testified during the trial
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7:05 - 7:09that they could see very well.
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7:09 - 7:12But this occurred in mid-January,
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7:12 - 7:18in the Northern Hemisphere, at 7 p.m. at night.
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7:18 - 7:21So when I did the calculations
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7:21 - 7:23for the lunar data and the solar data
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7:23 - 7:26at that location on Earth at the time of the incident
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7:26 - 7:28of the shooting, all right,
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7:28 - 7:31it was well past the end of civil twilight
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7:31 - 7:33and there was no moon up that night.
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7:33 - 7:35So all the light in this area from the sun and the moon
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7:35 - 7:38is what you see on the screen right here.
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7:38 - 7:41The only lighting in that area had to come
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7:41 - 7:44from artificial sources,
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7:44 - 7:47and that's where I go out and I do the actual reconstruction
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7:47 - 7:50of the scene with photometers, with various measures
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7:50 - 7:52of illumination and various other measures of
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7:52 - 7:56color perception, along with special cameras
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7:56 - 7:58and high-speed film, right?
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7:58 - 8:01Take all the measurements and record them, right?
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8:01 - 8:03And then take photographs, and this is what the scene
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8:03 - 8:05looked like at the time of the shooting
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8:05 - 8:07from the position of the teenagers
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8:07 - 8:11looking at the car going by and shooting.
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8:11 - 8:13This is looking directly across the street
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8:13 - 8:16from where they were standing.
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8:16 - 8:18Remember, the investigating officers' report said
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8:18 - 8:20the lighting was good.
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8:20 - 8:23The teenagers said they could see very well.
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8:23 - 8:26This is looking down to the east,
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8:26 - 8:30where the shooting vehicle sped off,
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8:30 - 8:35and this is the lighting directly behind the father
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8:35 - 8:37and the teenagers.
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8:37 - 8:41As you can see, it is at best poor.
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8:41 - 8:45No one's going to call this well-lit, good lighting,
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8:45 - 8:48and in fact, as nice as these pictures are,
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8:48 - 8:51and the reason we take them is I knew I was going to have to testify in court,
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8:51 - 8:55and a picture is worth more than a thousand words
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8:55 - 8:57when you're trying to communicate numbers,
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8:57 - 9:00abstract concepts like lux, the international measurement
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9:00 - 9:05of illumination, the Ishihara color perception test values.
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9:05 - 9:09When you present those to people who are not well-versed
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9:09 - 9:12in those aspects of science and that, they become
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9:12 - 9:14salamanders in the noonday sun. It's like
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9:14 - 9:17talking about the tangent of the visual angle, all right?
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9:17 - 9:20Their eyes just glaze over, all right?
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9:20 - 9:24A good forensic expert also has to be a good educator,
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9:24 - 9:26a good communicator, and that's part of the reason
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9:26 - 9:29why we take the pictures, to show not only
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9:29 - 9:31where the light sources are, and what we call the spill,
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9:31 - 9:34the distribution, but also so that it's easier
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9:34 - 9:38for the trier of fact to understand the circumstances.
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9:38 - 9:41So these are some of the pictures that, in fact,
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9:41 - 9:43I used when I testified,
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9:43 - 9:45but more importantly were, to me as a scientist,
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9:45 - 9:47are those readings, the photometer readings,
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9:47 - 9:52which I can then convert into actual predictions
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9:52 - 9:55of the visual capability of the human eye
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9:55 - 9:58under those circumstances,
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9:58 - 10:01and from my readings that I recorded at the scene
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10:01 - 10:04under the same solar and lunar conditions
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10:04 - 10:07at the same time, so on and so forth, right,
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10:07 - 10:08I could predict
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10:08 - 10:10that there would be no reliable color perception,
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10:10 - 10:12which is crucial for face recognition,
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10:12 - 10:15and that there would be only scotopic vision,
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10:15 - 10:17which means there would be very little resolution,
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10:17 - 10:19what we call boundary or edge detection,
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10:19 - 10:21and that furthermore, because the eyes would have been
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10:21 - 10:25totally dilated under this light, the depth of field,
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10:25 - 10:28the distance at which you can focus and see details,
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10:28 - 10:34would have been less than 18 inches away.
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10:34 - 10:36I testified to that to the court,
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10:36 - 10:39and while the judge was very attentive,
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10:39 - 10:41it had been a very, very long hearing
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10:41 - 10:46for this petition for a retrial, and as a result,
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10:46 - 10:48I noticed out of the corner of my eye
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10:48 - 10:52that I thought that maybe the judge was going to need
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10:52 - 10:54a little more of a nudge
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10:54 - 10:56than just more numbers.
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10:56 - 10:59And here I became a bit audacious,
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10:59 - 11:00and I turned
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11:00 - 11:03and I asked the judge,
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11:03 - 11:05I said, "Your Honor, I think you should go out
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11:05 - 11:08and look at the scene yourself."
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11:08 - 11:11Now I may have used a tone which was more like a dare
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11:11 - 11:13than a request — (Laughter) —
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11:13 - 11:18but nonetheless, it's to this man's credit and his courage
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11:18 - 11:21that he said, "Yes, I will."
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11:21 - 11:25A shocker in American jurisprudence.
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11:25 - 11:28So in fact, we found the same identical conditions,
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11:28 - 11:30we reconstructed the entire thing again,
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11:30 - 11:34he came out with an entire brigade of sheriff's officers
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11:34 - 11:39to protect him in this community, all right? (Laughter)
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11:39 - 11:44We had him stand actually slightly in the street,
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11:44 - 11:47so closer to the suspect vehicle, the shooter vehicle,
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11:47 - 11:50than the actual teenagers were,
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11:50 - 11:52so he stood a few feet from the curb
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11:52 - 11:55toward the middle of the street.
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11:55 - 11:58We had a car that came by,
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11:58 - 12:03same identical car as described by the teenagers, right?
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12:03 - 12:05It had a driver and a passenger,
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12:05 - 12:08and after the car had passed the judge by,
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12:08 - 12:12the passenger extended his hand,
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12:12 - 12:16pointed it back to the judge as the car continued on,
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12:16 - 12:19just as the teenagers had described it, right?
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12:19 - 12:22Now, he didn't use a real gun in his hand,
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12:22 - 12:24so he had a black object in his hand that was similar
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12:24 - 12:26to the gun that was described.
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12:26 - 12:29He pointed by, and this is what the judge saw.
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12:29 - 12:36This is the car 30 feet away from the judge.
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12:36 - 12:39There's an arm sticking out of the passenger side
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12:39 - 12:41and pointed back at you.
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12:41 - 12:43That's 30 feet away.
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12:43 - 12:45Some of the teenagers said that in fact the car
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12:45 - 12:48was 15 feet away when it shot.
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12:48 - 12:52Okay. There's 15 feet.
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12:52 - 12:56At this point, I became a little concerned.
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12:56 - 13:00This judge is someone you'd never want to play poker with.
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13:00 - 13:05He was totally stoic. I couldn't see a twitch of his eyebrow.
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13:05 - 13:08I couldn't see the slightest bend of his head.
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13:08 - 13:12I had no sense of how he was reacting to this,
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13:12 - 13:15and after he looked at this reenactment,
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13:15 - 13:16he turned to me and he says,
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13:16 - 13:19"Is there anything else you want me to look at?"
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13:19 - 13:23I said, "Your honor," and I don't know whether I was
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13:23 - 13:26emboldened by the scientific measurements that I had
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13:26 - 13:30in my pocket and my knowledge that they are accurate,
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13:30 - 13:32or whether it was just sheer stupidity,
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13:32 - 13:35which is what the defense lawyers thought — (Laughter) —
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13:35 - 13:37when they heard me say,
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13:37 - 13:40"Yes, Your Honor, I want you stand right there
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13:40 - 13:44and I want the car to go around the block again
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13:44 - 13:47and I want it to come and I want it to stop
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13:47 - 13:51right in front of you, three to four feet away,
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13:51 - 13:55and I want the passenger to extend his hand
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13:55 - 13:57with a black object and point it right at you,
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13:57 - 14:03and you can look at it as long as you want."
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14:03 - 14:07And that's what he saw. (Laughter)
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14:07 - 14:11You'll notice, which was also in my test report,
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14:11 - 14:14all the dominant lighting is coming from the north side,
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14:14 - 14:15which means that the shooter's face would
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14:15 - 14:18have been photo-occluded. It would have been backlit.
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14:18 - 14:20Furthermore, the roof of the car
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14:20 - 14:24is causing what we call a shadow cloud inside the car
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14:24 - 14:27which is making it darker.
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14:27 - 14:32And this is three to four feet away.
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14:32 - 14:35Why did I take the risk?
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14:35 - 14:39I knew that the depth of field was 18 inches or less.
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14:39 - 14:41Three to four feet, it might as well have been
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14:41 - 14:45a football field away.
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14:45 - 14:47This is what he saw.
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14:47 - 14:51He went back, there was a few more days of evidence
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14:51 - 14:53that was heard. At the end of it,
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14:53 - 14:56he made the judgment that he was going to grant
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14:56 - 14:59the petition for a retrial.
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14:59 - 15:02And furthermore, he released Mr. Carrillo
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15:02 - 15:05so that he could aid in the preparation of his own defense
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15:05 - 15:11if the prosecution decided to retry him.
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15:11 - 15:13Which they decided not to.
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15:13 - 15:18He is now a freed man. (Applause)
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15:18 - 15:22(Applause)
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15:22 - 15:27This is him embracing his grandmother-in-law.
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15:27 - 15:31He -- His girlfriend was pregnant when he went to trial,
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15:31 - 15:35right? And she had a little baby boy.
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15:35 - 15:38He and his son are both attending Cal State, Long Beach
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15:38 - 15:44right now taking classes. (Applause)
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15:44 - 15:48And what does this example --
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15:48 - 15:52what's important to keep in mind for ourselves?
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15:52 - 15:56First of all, there's a long history of antipathy
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15:56 - 15:58between science and the law
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15:58 - 16:01in American jurisprudence.
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16:01 - 16:04I could regale you with horror stories of ignorance
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16:04 - 16:08over decades of experience as a forensic expert
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16:08 - 16:13of just trying to get science into the courtroom.
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16:13 - 16:18The opposing council always fight it and oppose it.
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16:18 - 16:21One suggestion is that all of us become much more
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16:21 - 16:24attuned to the necessity, through policy,
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16:24 - 16:26through procedures,
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16:26 - 16:29to get more science in the courtroom,
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16:29 - 16:32and I think one large step toward that
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16:32 - 16:33is more requirements,
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16:33 - 16:36with all due respect to the law schools,
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16:36 - 16:41of science, technology, engineering, mathematics
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16:41 - 16:43for anyone going into the law,
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16:43 - 16:47because they become the judges.
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16:47 - 16:50Think about how we select our judges in this country.
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16:50 - 16:53It's very different than most other cultures. All right?
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16:53 - 16:55The other one that I want to suggest,
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16:55 - 16:58the caution that all of us have to have,
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16:58 - 17:00I constantly have to remind myself,
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17:00 - 17:03about just how accurate are the memories
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17:03 - 17:08that we know are true, that we believe in?
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17:08 - 17:12There is decades of research,
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17:12 - 17:16examples and examples of cases like this,
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17:16 - 17:18where individuals
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17:18 - 17:21really, really believe. None of those teenagers
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17:21 - 17:23who identified him
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17:23 - 17:26thought that they were picking the wrong person.
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17:26 - 17:30None of them thought they couldn't see the person's face.
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17:30 - 17:32We all have to be very careful.
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17:32 - 17:35All our memories are reconstructed memories.
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17:35 - 17:38They are the product of what we originally experienced
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17:38 - 17:41and everything that's happened afterwards.
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17:41 - 17:43They're dynamic.
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17:43 - 17:45They're malleable. They're volatile,
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17:45 - 17:49and as a result, we all need to remember to be cautious,
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17:49 - 17:52that the accuracy of our memories
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17:52 - 17:56is not measured in how vivid they are
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17:56 - 18:01nor how certain you are that they're correct.
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18:01 - 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 |