You have seen countless police lineups on TV shows and movies. The practice of bringing in one suspect along with four or five "fillers" and lining them up along a wall marked with heights is being questioned by research findings and defence lawyers. Everything about which persons/images are chosen for a lineup and how they are presented affects the likelihood of witnesses selecting the real culprit rather than identifying an innocent person.
In practice, police rarely bring in live people for a lineup. It is much more common for a photo lineup to be used. I remember pulling together 6-packs for some of my cases years ago. This was a term used to describe a single page showing the photos of six possible suspects at one time. Research now suggests that there are two big problems with the procedure I used: the method and the administrator.
Whether using live people or photographic images, there are two primary methods of presenting a group of possible suspects to a witness. They are simultaneous and sequential. The simultaneous method, as pictured in the silly photo above, shows all of the five or six possible suspects to the witness at one time. The problem: people tend to compare the faces to each other. Even if the perpetrator is not in the lineup, the witness is inclined to choose the closest match.
"While we like to think that our eyes won't mislead us, mistaken eyewitness identification accounts for more than 70% of wrongful convictions that are ultimately overturned by...more objective DNA evidence" (Time.com).
The sequential lineup method, shows each suspect individually. The witness is forced to compare the person to his/her memory, rather than to people next to them. According to David Harris of the University of Pittsburgh Law School, "Agencies should bring in suspects one at a time" (Minnesota.publicradio.org). However, he is not suggesting that the suspect should be the only person presented to the witness.
Maurice Caldwell spent 20 years in prison for murder based on eyewitness testimony. Of four witnesses, only one identified him, but that one identification persuaded the jury despite a lack of physical or forensic evidence. Caldwell was seen in the area after the crime was reported. Police brought him to the witness and they asked her if he was the man she had seen. The process confirmed in her mind that he was involved in the crime (CBSlocal.com).
According to a CBS affiliate in San Francisco, "Even without realizing it, an investigator can send nonverbal cues to the eyewitness." It may be a deep breath, the way they lean, or a facial expression. The one way to completely guard against this influence is to have an uninvolved officer administer a sequential lineup.
A police officer who does not know which image is the actual suspect cannot manipulate the witness's response. This is called a double-blind lineup. Dallas police have taken this to the extreme. They have a special unit that does only lineups. They are not involved in investigations and therefore will not influence the witnesses. They have specialized training and follow written procedures for each lineup that include showing photos sequentially (NYTimes.com).
It is imperative that a move toward double-blind, sequential lineups be made standard practice. For more details, you can watch a segment of Rock Center called "Photo ID: Are Police Lineups Reliable?" at this link.
When Caldwell's case was reopened, another man came forward and confessed to the murder. Caldwell is now arguing that his civil rights were violated in a lawsuit against the city of San Francisco. It is unconscionable that a murder case had even gone to trial with so little evidence.
Next week: More of the latest research findings on eyewitness identifications.
- CBS 5, "Man Wrongly Convicted In SF Murder Questions Police Lineups," Sanfrancisco.cbslocal.com, 5-7-2012.
- Goode, Erica and John Schwartz, "Police Lineups Start to Face Fact: Eyes Can Lie," NYTimes.com, 8-28-2011.
- Guy, Shoshana, "Police Photo Lineups Challenged after Series of Wrongful Convictions," Rock Center, 4-4-2012.
- Szalavitz, Maria, "How to Improve Police Lineups and ID the Right Culprit," Time.com, 9-4-2012.
- Weber, Tom, "Do We Do Police Lineups Correctly?" Minnesota.publicradio.org, 11-8-2012.