Flaws seen in police use of mug shot search
Inside a police station house in New York City about a year ago, St. Clair Steward insisted he had not been involved in a recent shooting. Steward told the police he had been resting at home.
Investigators did not believe him. The motive behind the shooting was a mystery, but the victim had combed through pictures of people with past arrests and identified Steward, a father of eight, as the assailant.
To the detectives involved, the shooting in January 2018 was just the latest in a long line of crimes solved by asking a victim to search through mug shots, an investigative technique used in New York for more than 150 years. Detectives enter a description of the perpetrator into a database, which then spits out dozens or even hundreds of matching photos. The witness scrolls through, in hopes of recognizing the culprit.
But these open-ended photo searches also increase the likelihood of ensnaring an innocent person, according to studies and experts in eyewitness identification. The method has few safeguards to protect against a false identification and can lead police to focus on the wrong person from the outset of an investigation.
Many of the nation’s other large police departments said they do not rely on the technique, a New York Times survey shows.
Detective bureaus in many other jurisdictions do not show booking photos to witnesses until they have a suspect in mind. Investigators then conduct a photo lineup, placing the suspect’s among photos of at least five “fillers” – people who fit the description but are known to be innocent.
That approach offers some shield against a false identification: If the witness chooses a filler, police understand the witness is wrong and know not to arrest that person.
In a mug shot search, everyone is a potential suspect, and the actual culprit might not be among the group. But whoever the witness selects becomes the focus of the investigation.
“I think it taints the investigation,” said Deputy Chief Thomas Castro, who oversees detectives for the Dallas Police Department.
Dermot Shea, New York City’s chief of detectives, defended his department’s use of the searches, saying they were just one of many investigative tools.
“Mug shots are still a piece of the puzzle,” Shea said. “But to me, they are a much smaller piece.”
In Steward’s case, in the borough of Queens, detectives entered broad search parameters into the database. The victim chose Steward, whose photo was the 31st to appear, said a law enforcement official who asked to remain anonymous because the official was not authorized to discuss the case.
“They told me, ‘The person looked at your mug shot and said it was you,’ ” Steward, 43, said in a recent interview.
Police then put Steward in a lineup alongside several other men. Again, the victim chose Steward. He was charged with attempted murder and jailed.
He stayed in jail for more than two months until a DNA sample from the crime scene was finally tested. The sample, believed to have come from the culprit, did not match Steward, throwing the case into doubt. Prosecutors quietly dismissed the charges in September.