I recall a Seinfeld episode in which Kramer is hired to stand on a police line-up and actually fingered as the criminal–how does this compare to how line-ups are actually done? Who are the “extras”, if there actually are any at all?
Generally speaking, the police already have a suspect in custody when they do a lineup. They then include this individual in a lineup with typically 4 or 5 other volunteers who resemble the suspect in both size and appearance. The witness is asked to identify the person they saw commit the crime in question. In cases where the witness fingers the wrong person, the police may further investigate the individual, but simply being identified in a lineup is not, on it’s own, grounds for an arrest.
That helps, but then how are volunteers selected?
Also, many police nowadays use “six packs” - which is a photo array. Basically you take a polaroid of your suspect. You take that photograph and 5 photographs of similar sized/shaped/etc people (which you have taken beforehand). Then you show those to the potential witness - and they can finger the picture.
It’s just a cheaper / less hasslesome way.
Here’s a good Slate article about police lineups and identification procedures. It deals with how the extras are selected.
Appearance.
They could be cops or criminals currently in prison/jail.
What motivation would a prisoner have to volunteer for a police lineup? It seems to me that your average prisoner would probably resent and mistrust the police and thus not wish to cooperate with them by volunteering.
Boredom? It’s something new to do that gets them out of their cells for a while.
In NYPD Blue, they quite frequently get line-up fillers from local homeless shelters.
While i realize that basing one’s answer on a TV show is rather problematic, the primary consultant (and a producer) on the show was a retired NYPD detective (Bill Clarke), and i’m sure little details like this are pretty representative of what really happens.
Doctor Who’s linked article also says that New York cops can pay members of the public $10 to stand in a line-up, so the idea that they might get people from a shelter certainly isn’t too surprising.
One of my classes is taught by the Chief Trial Deputy for the DA’s office here.
According to him, it’s key that the participants all look alike; inmates and officers have been mentioned, but also attorneys (prosecution or defense): i.e., whoever is available and looks like the suspect is a candidate.
A better source, though, agrees with mhendo :
“How many times have you been in a line-up? It’s always you and four dummies. The P.D. pays homeless guys ten bucks a head half the time.”
–The Usual Suspects
Yup, appearance is the most important thing. If they dont look similar, it wont hold up in court. The other important thing is ‘alibi’. The problem with the homeless shelter thing is if one is picked, then you have to wonder “Where was this guy on the night in question??” Cause maybe now you have a new suspect. Lawyers, cops, and inmates are all better options cause they are readily available and have verifiable alibis.
If someone fingers a cop or lawyer lineup volunteer, you still might have to go through the time and expense of investigating his alibi depending upon the circumstances of the case and the certainty of the eyewitness. It might not be as common as in the general population, but cops and lawyers do occasionally commit crimes, even violent ones.
Yea. But I think the idea is that there are pleanty of honest people who knew where they were that day. Especially if they were at work.
… hopefully anyway.
I have a hard time believing they’d open an investigation on a homeless guy if he was fingered in a line up. All you really said is, of the five or six people available, he looks most like the guy I think I saw. Let’s say the victim thinks he saw a 6’ 200 lbs white male with short dark hair… they have their suspect and the rest, and the victim picks one of the others guys. There’s thousands of other people that fit that description and have no alibi. And then you’re left wondering why a guy who is guilty of a crime and they’re looking for someone that looks like him would be doing volunteering for a lineup anyway. My guess is that if the crook is picked out of the lineup, the prosecution will bring that up in court; if he isn’t, they probably just attribute it to victim distress, poor or short viewing, or any other number of factors. I can’t imagine they’d do a lineup and rest the whole case on whether or not the person was fingered. Un doubtedly they’d have more evidence on anyone who isn’t fingered than the poor sap who got fingered in his stead.
Err…
Undoubtedly, they’d have more evidence on the guy they wanted picked out, but wasn’t, than the poor innocent sap who got fingered in his stead.
When I was at college in Wales, there was a cop shop over the street from the college. The police would occasionally turn up in our common room - giving those of us carrying marijuana heart attacks - to ask for volunteers for line-ups. We would get paid £5 for about 1 hour’s “work”. It was a bit scary sitting around with possible violent offenders, as we were all in the same waiting room, and it was quite clear who were the suspects and who were the students.
I wasn’t actually trying to make it seem like a huge problem. I just said wonder not prosecute. 
The one time I had to identify people in a photo lineup, I learned that being too observant a witness can cause problems. My 911 call identified two males between the ages of 18 and 21 with X skin tone, wearing hooded sweatshirts, with Y hair and I got their height and other things right as well. When I got picked up to go to the police station in the middle of the night, I watched them put together a photo lineup out of a database using my great descriptions. They ended up giving me a sheet of about 40 virtual clones to choose from. I agonized over it for a good 45 minutes before I signed my choices. I have no idea how I did it but I got them both right. (this was for an attempted armed robbery where I only saw their faces for a few seconds).
They use extras.
Except of course in the Duke Lacrosse rape case where the lineup was 100% Duke Lacrosse players.
It seems like I read a story or saw a TV show . . . I can’t remember which. It was about a lawyer who had killed someone, but they arrested the wrong guy and put him in a line up. One of the fill-ins in the line up was, you guessed it, the lawyer. The eye witness fingered the lawyer, and cops wrote it off as a misidentification.
Darn, I wish I could remember where I saw it.