The murder happened a little over 21 years ago on January 18th 1991.
In a small bedroom community of Lynwood, California,
just a few miles southeast of Los Angeles.
Father came out of his house to tell his teenage son and his five friends
that it was time for them to stop horsing around
on the front lawn and on the sidewalk,
to get home, finish their school work,
prepare themselves for bed.
And as the father was administering these instructions, a car drove by, slowly.
And just after it passed the father and the teenagers, a hand went out
from the front passenger window and Bam! Bam!, killing the father.
And the car sped off.
The police investigating officers were amazingly efficient.
They considered all the usual culprits,
and in less than 24 hours they had selected their suspect;
Francisco Carrillo, a seventeen-year-old kid,
who lived about two or three blocks away from where the shooting occurred.
They found photos of him, they prepared a photo array,
and the day after the shooting they showed it to one of the teenagers
and he said, "That's the picture, that's the shooter I saw that killed the father."
That was all a preliminary hearing judge had to listen to,
to bind Mr Carrillo over to stand trial for a first-degree murder.
In the investigation that followed before the actual trial,
each of the other five teenagers was shown photographs, the same photo array.
The picture that we best can determine was probably the one that they were shown
in the photo array is in your bottom left-hand corner of these mugshots.
The reason we're not sure absolutely
is because of the nature of evidence preservation in our judicial system.
But that's another whole TEDxTalk for later.
So, at the actual trial all six of the teenagers testified
and indicated identifications they had made in the photo array.
He was convicted, he was sentenced to life imprisonment,
and transported to Folsom prison.
So what's wrong? Straightforward, fair trial, full investigation.
Oh yes, no gun was ever found.
No vehicle was ever identified
as being the one in which the shooter had extended his arm,
and no person was ever charged with being the driver of the shooter's vehicle.
And Mr Carrillo's alibi?
Which of those parents here in the room might not lie
concerning the whereabouts of your son or daughter in an investigation of a killing?
Sent to prison, adamantly insisting on his innocence,
which he has consistently for 21 years.
So what's the problem?
The problems actually for this kind of case come manifold
from decades of scientific research involving human memory.
First of all we have all the statistical analysis
from the Innocence Project work, where we know
that we have, what, 250, 280 documented cases now,
where people have been wrongfully convicted
and subsequently exonerated, some from death row,
on the basis of later DNA analysis.
And you know that over three-quarters of all of those cases of exoneration
involved only eye-witness identification testimony
during the trial that convicted them.
We know that eye-witness identifications are fallible
The other comes from an interesting aspect of human memory,
that's related to various brain functions,
but I can sum up for the sake of brevity here in a simple line:
the brain abhors a vacuum.
Under the best of observation conditions, the absolute best,
we only detect, encode and store in our brains,
bits and pieces of the entire experience in front of us,
and they're stored in different parts of the brain.
So now when it's important
for us to be able to recall what it was that we experienced,
we have an incomplete, we have a partial store, and what happens?
Below awareness, with no requirement for any kind of motivated processing,
the brain fills in information that was not there, not originally stored,
from inference, from speculation, from sources of information
that came to you as the observer after the observation.
But it happens without awareness such that you aren't cognizant of it occurring.
It's called reconstructed memories. It happens to us
in all the aspects of our lives, all the time.
Let me ask you to consider the horrific events of 9/11.
Think about when you first got the information about this catastrophe,
how you felt and more importantly,
when was first time you saw the second trade tower imploding collapse,
after the first trade tower had gone down?
If you're like most Americans, myself included,
you have a very clear memory
that you saw the first tower come down and then you saw
the second tower finally collapse after the other plane crashed into it
within an hour or two afterwards.
I remember vividly where I was. I was down at LAX,
at the satellite terminal for American Airlines,
waiting to get on an airplane to fly to San Diego.
Of course, all the air traffic was ceased.
And so I had nothing to do but to sit and watch the television monitors
with all of the news broadcasts over and over and over again.
Of the horrendous events and I know I saw that second trade tower come down
an hour or two after the first.
And all of the research we have indicates that most Americans too,
except for a few people that live in certain places in New York.
And you know something? That's a totally false memory.
It could not be something you experience,
there was absolutely no media footage
of the second trade tower collapsing until over 24 hours after the event.
But in fact you know intellectually, cognitively,
that they did occur fairly close in time.
You did know about and see the first one, you did see the second one;
but you didn't see it until over a day later at the earliest.
But the brain without you being aware has pulled them together,
and you believe you saw them very close in time.
It is a reconstructed memory, not an accurate memory.
No matter how vivid, no matter how sure you are,
it was those two considerations among others,
reconstructed memory, the fact about the eye-witness fallibility,
that was part of the instigation for a group of appeal attorneys
led by an amazing lawyer, named Ellen Eggers,
to pool their experience and accounts together and petition the superior court
for a retrial for Francisco Carrillo.
They retained me as a forensic neurophysiologist
because I had expertise
in eye-witness memory identification, which obviously makes sense for this case,
but also because I'd expertise and testify about the nature of human night vision.
Well, what's that got to do with this?
Well, when you read through the case materials in this Carrillo case,
one of the things that suddenly strikes you is that
the investigating officers said the lighting was good
at the crime scene, at the shooting.
All the teenagers testified during the trial
that they could see very well.
But this occurred in mid-January, in the northern hemisphere,
at 7 pm at night.
So when I did the calculations,
at that location on Earth at the time of the incident of the shooting,
it was well past the end of civil twilight and there was no moon up the night.
So all the light in this area from the sun and the moon
is what you see on the screen right here.
The only lighting in that area had to come from artificial sources.
And that's where I go out and I do the actual reconstruction of the scene
with photometers, with various measures of illumination
and various other measures of power perception
along with special cameras and high-speed film;
take all the measurements and record them, and then take photographs.
and this is what the scene looked like at the time the of the shooting
from the position of the teenagers
looking at the car going by and shooting.
This is looking directly across the street,
remember the investigating officer's report said the lighting was good;
teenagers said they could see very well.
This is looking directly across the street from where they were standing.
This is looking down to the east where the shooting vehicle sped off.
And this is the lighting directly behind the father and the teenagers.
As you can see it is at best poor.
No one is gonna call this well-lit, good lighting
and in fact as nice as these pictures are and the reason we take them
is I knew I was going to have to testify in court.
And a picture is worth more than a thousand words
when you're trying to communicate numbers, abstract concepts like lux,
the international measurement of illumination,
the Ishihara color are color perception test values.
When you present those to people who are not well-versed
in those aspects of science and that,
they become salamanders in the noonday sun.
It's like talking about the tangent of the visual angle;
their eyes just glaze over.
A good forensic expert also has to be a good educator,
a good communicator and that's part of the reason why we take the pictures
to show not only where the light sources are
and what we call the spill, the distribution,
but also so that it's easier for the trier of fact
to understand the circumstances.
So these are some of the pictures that in fact I use when I testify.
But more importantly were to me, the scientists, are those readings,
the photometer readings, which I can then convert
into actual predictions of the visual capability of the human eye
under those circumstances. And from my readings
that I recorded at the scene under the same solar and lunar conditions
at the same time and so on and so forth,
I could predict that there would be no reliable color perception
which is crucial for face recognition.
And that there would only be scotopic vision
which meant there'd be very little resolution
which we call boundary or edge detection,
and furthermore because the eyes would have been totally dilated
under this light, the depth of field,
the distance at which you can focus and see details
would have been less than 18 inches away.
I testified to that to the court
and while the judge was very attentive, it had been a very, very long hearing
for this petition for a retrial.
And as a result I'd noticed out of the corner of my eye
that I thought that maybe the judge was going to need a little more of a nudge
than just more numbers.
And here I became a bit audacious and I turned and I asked the judge,
I said, "Your honor, I think you should go out and look at the scene yourself."
Now I may have used a tone which was more like a dare than a request,
but nonetheless it's to this man's credit and his courage,
that he said, "Yes, I will" a shocker in American jurisprudence.
So in fact we found the same identical conditions,
we reconstructed the entire thing again,
he came out with an entire brigade of sheriff's officers
to protect him in this community. (Laughter)
We had him stand actually slightly in the street, so closer
to the shooter vehicle than the actual teenagers were.
So he stood a few feet from the curb
toward the middle of the street.
We had a car that came by,
same identical car as described by the teenagers.
It had a driver and a passenger,
and after the car had passed the judge by,
the passenger extended his hand,
pointed it back to the judge,
as the car continued on, just as the teenagers had described it.
Now, we didn't use a real gun in his hand,
we thought the sheriff's department would probably question the necessity
for that kind of realism.
So we had a black object in his hand that was similar to the gun that was described.
He pointed, Bam! And this is what the judge saw.
This is the car 30 feet away from the judge.
There's an arm sticking out of the passenger side
and pointed back at you. That's 30 feet away.
Some of the teenagers just said that in fact
the car was 15 feet away when it shot.
There's 15 feet.
At this point I became a little concerned.
This judge is someone you'd never wanna play poker with.
He was totally stoic.
I couldn't see a twitch of his eyebrow,
I couldn't see the slightest bend of his head.
I had no sense of how he was reacting to this.
And after he looked at this re-enactment,
he turned to me and he says, "Is there anything else you want me to look at?"
I said, "Your Honor," and I don't know whether I was emboldened,
by the scientific measurements that I had in my pocket,
and my knowledge that they are accurate,
or whether it was just sheer stupidity, which is what the defense lawyers thought
when they heard me say, "Yes Your Honor, I want you to stand right there.
I want the car to go around the block again.
And I want it to come, and I want it to stop right in front of you,
three to four feet away and I want the passenger
to extend his hand with a black object, point right at you,
and you can look at it as long as you want."
And that's what he saw. (Laughter)
You'll notice, which was also in my test report,
all the dominant lighting is coming from the north side
which means that the shooter's face would have been photo occluded,
would have been backlit. Furthermore, the roof of the car
is causing what we call a shadow cloud inside the car,
which is making it darker.
And this is three to four feet away.
Why did I take the risk?
I knew the depth of field was 18 inches or less.
Three to four feet; it might as well have been a football field away.
This is what he saw, went back,
there was a few more days of evidence that was heard.
At the end of it, he made the judgment
that he was going to grant the petition for a retrial,
and furthermore he released Mr Carrillo
so he could aid in the preparation of his own defense
if the prosecution decided to retry him.
Which they decided not to. He is now a freed man.
(Applause)
This is him embracing here his grandmother-in-law.
His girlfriend was pregnant when he went to trial
and she had a little baby boy.
He and his son are both attending Cal State, Long Beach,
right now, taking classes.
(Applause)
What does this example, what's important to keep in mind for ourselves?
First of all there's a long history of antipathy between science and the law
in American jurisprudence.
I could regale you with horror stories of ignorance.
Over decades of experience as a forensic expert,
of just trying to get science into the courtroom,
deposing council always fighting an opposer.
One suggestion is that all of us become much more attuned
to the necessity, through policy, through procedures,
to get more science in the courtroom.
And I think one large step toward that is more requirements,
with all due respect to the law schools,
of science, technology, engineering, mathematics,
for anyone going into the law because they become the judges.
Think about how we select our judges in this country,
it's very different than most other cultures.
The other ones I wanna suggest, the caution that all of us have to have,
I constantly have to remind myself
about just how accurate are the memories that we know are true,
that we believe in.
There is decades of research, examples and examples of cases like this,
where individuals really, really believe.
None of those teenagers who identified him
thought that they were picking the wrong person,
none of them thought they couldn't see the person's face.
We all have to be very careful.
You just saw a marvelous film about all kinds of complexities of memory,
It is an enormously confusing
and difficult set of processes and principles that are involved.
All our memories are reconstructed memories.
They are the product of what we originally experienced
and everything that's happened afterwards.
They're dynamic, they're malleable, they're volatile, and as a result
we all need to remember to be cautious.
That the accuracy of our memories is not measured in how vivid they are
nor how certain you are that they're correct.
I'm sure I saw the second trade tower collapse an hour later,
but I know it could not have happened.
Thank you.
(Applause)