By Chief William G. Brooks III*
In the words of U.S. Supreme Court justice William Brennan, there is “nothing more convincing than a live human being who takes the stand, points a finger at the defendant, and says ‘That’s the one!'” But we now know that such compelling evidence can be wrong. According to the Innocence Project, of the 336 prisoners freed after DNA proved they were innocent, over 70% went to prison after an eyewitness mistakenly identified them as the offender. In other words, faulty identifications by witnesses account for more wrongful convictions than any other cause.
Things are actually worse than they appear. Most of those defendants were serving time for homicides and sex assaults, crimes that frequently yield DNA evidence. If so many innocent people were serving time for these crimes, how many are in prison for crimes like robberies and shootings, where DNA evidence is scant? The National Registry of Exonerations maintained by the University of Michigan Law School lists over 1,700 defendants whose cases have been overturned by both DNA and other methods. And while erroneous convictions ruin the lives of innocent defendants and taint the reputation of the courts and police, they also leave true offenders on the street. The DNA that exonerated about half of those 336 defendants identified the actual perpetrators, and those criminals were eventually convicted of committing over 140 violent crimes in addition to the ones that sent innocent people to prison.
Mistakes by eyewitnesses are not always the fault of the police; recognizing a stranger you saw only once is a difficult task, and so-called “estimator variables” such as distance, poor lighting, stress and “own race bias” can make it more so. On the other hand “system variables,” or those procedures used by police officers during show-ups and photo arrays, can have significant impact.
I spend a lot of time these days presenting to officers in other states about science-based protocols they can employ to reduce the chance of eyewitness error. While the full scope of the reform measures is too complex to fully explore here, it includes several fundamental changes. First, officers should read specific instructions to witnesses prior to show-ups and photo arrays. This recommendation also facilitates compliance with discovery rules that require disclosure of what the officer said to the witness prior to an identification. Further, other procedures urge that photos be shown one at a time, and by an officer who does not know which photo is of the suspect. The recommendation that a detective not show his own photo arrays can stir the ire of veteran detectives, and it did mine ten years ago until I came to understand the compelling reasons for it. Finally, it is imperative that an officer ask a witness how certain she is of an identification as soon as it is made, before extraneous information can taint her assessment.
There are other precautions departments can take to reduce the likelihood of error. My department, for instance, never uses composites. Those transparency overlays of facial features are seldom helpful, and research has shown that the procedure of assembling one can damage the witness’s memory for the offender’s face.
The good news is that Massachusetts police have largely embraced the science. A 2013 survey showed that about 85% of responding police departments had modern, reform-based policies. All Massachusetts police academies are required to teach recruits research-based procedures, and training is mandated this year for every active-duty municipal police officer.
This is not an area where society can rely on the courts alone to find the truth. That witness who testifies “that’s the one” provides compelling evidence indeed, and it is the responsibility of the police to ensure our procedures and training are supported by science.
* Chief William G. Brooks is the Chief of the Norwood, MA Police Department and is a member of the Massachusetts Supreme Judicial Court’s Standing Committee on Eyewitness Identification. Chief Brooks also presents on behalf of the Innocence Project, and received the Innocence Network’s Champion of Justice Award in 2012 for his work in eyewitness identification.