Why eyewitness get it wrong

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 color perception, along with special cameras and high-speed film, right? Take all the measurements and record them, right?

And then take photographs, and this is what the scene looked like at the time of the shooting from the position of the teenagers looking at the car going by and shooting.

This is looking directly across the street from where they were standing. Remember, the investigating officers' report said the lighting was good. The teenagers said they could see very well. 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's going to 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 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, all right?

Their eyes just glaze over, all right? 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 used when I testified, but more importantly were, to me as a scientist, 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, so on and so forth, right, I could predict that there would be no reliable color perception, which is crucial for face recognition, and that there would be only scotopic vision, which means there would be very little resolution, what we call boundary or edge detection, and that 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 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 — Laughter — but nonetheless, it's to this man's credit and his courage that he said, "Yes, I will. 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, all right?

Laughter We had him stand actually slightly in the street, so closer to the suspect vehicle, 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, right? 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, right? Now, he didn't use a real gun in his hand, so he had a black object in his hand that was similar to the gun that was described.

He pointed by, 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 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 want to 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 reenactment, 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 — Laughter — when they heard me say, "Yes, Your Honor, I want you stand right there and 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 and point it right at you, and you can look at it as long as you want.

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. It 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? Albright cautions that the research in some areas is still in flux. For example, an early study praised the use of sequential lineups, in which possible perpetrators are shown one by one, because it cut down on false identification.

But follow-up work showed that the approach cut down on all identifications, false or accurate. Now, the pendulum has swung back toward recommending simultaneous viewing.

That said, some of the changes that the report recommends focus on the key point in the process: the initial identification in a police lineup. It calls for making the procedure "blind," meaning that the police running it are not involved in the case and have no idea about who the potential suspect might be. The procedure should be videotaped, and the witness' confidence in the identification should be ascertained at the time.

Albright cites a case where a person who was uncertain at a lineup later went on to express complete certainty in their mistaken identification in court.

The courts can also play a role through the instructions they give to both witnesses and juries. Witnesses can be instructed in ways that help provide a consistent and conservative response and include a sense of uncertainty.

Juries can be informed of some of the limits of eyewitness testimony. Albright is somewhat optimistic about the potential for change, citing two recent state court decisions that improved the scientific foundations for allowing eyewitness testimony.

But he notes that for federal courts, the Supreme Court has set a standard for eyewitness testimony back in , and it was based on legal precedent rather than science. There are no obvious means of updating that standard.

But ultimately, the most significant recommendations in the report have to be implemented at the level of thousands of individual police departments across the country.

While courts can help drive that process, the change will only be possible if these departments value accuracy over a possibly inflated chance of getting any sort of identification. PNAS , Thanks for reading Scientific American. Create your free account or Sign in to continue. See Subscription Options. Go Paperless with Digital. Here are some of them: Extreme witness stress at the crime scene or during the identification process. Presence of weapons at the crime because they can intensify stress and distract witnesses.

Use of a disguise by the perpetrator such as a mask or wig. A racial disparity between the witness and the suspect. Brief viewing times at the lineup or during other identification procedures. A lack of distinctive characteristics of the suspect such as tattoos or extreme height. Get smart. Sign up for our email newsletter. Sign Up. Support science journalism.

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