Highly publicized DNA exonerations have heated up debate about the best practices for obtaining eyewitness evidence using police lineups. Law enforcement, prosecutors, defense attorneys, researchers, politicians, legal scholars and the courts are all weighing in.
Eyewitness evidence and police lineups are getting heightened scrutiny because mis-identification by eyewitnesses was the leading cause of more than 75% of the wrongful convictions brought to light. (1st web link below)
Who’s debating what.
There is some conflict within the existing research about what practices in police lineups would make eyewitness identifications more reliable. Research is ongoing. (1st and 2nd web links below) While everyone agrees that no one wants innocent people wrongfully convicted, the current state of the research leaves room for disagreement on the methods and means for preventing that.
Not surprisingly, the defense bar appears to agree within its ranks that best practices should be mandated – by courts or legislature – and they’re working to accomplish that. They also appear united that the most stringent practices supported by research are the best ones.
Law enforcement has been divided in its responses to the research and to reform that would mandate specific policies and procedures. A bill to standardize police lineups in Florida failed just this month – defeated by intense law enforcement lobbying. Florida law enforcement conceded that written policies for how to obtain eyewitness evidence are a good idea but successfully argued that individual agencies should have discretion in developing and implementing them. (3rd web link below)
Differing views among law enforcement leaders on what agencies should be required to do to improve the reliability of eyewitness evidence have been published in Police Chief Magazine. (4th web link below)
Some law enforcement agencies have implemented pilot programs and studies to evaluate how different lineup practices work in the field. Others have voluntarily committed to implementing policies and procedures recommended by the research. (1st and 5th web links below)
A police pilot program added to the debate because it suggested that lab results were not supported by results in the field. Researchers had compared simultaneous and sequential lineups. Simultaneous lineups show the eyewitness all the photos or people at the same time. Sequential lineups present a photo or subject to the witness one at a time.
Some researchers asserted that during simultaneous lineups, witnesses use relative judgment - they compare lineup photos to each other rather than to their memory of the perpetrator. This is a problem if the actual perpetrator isn’t in the lineup because witnesses will often pick the lineup subject who most closely resembles the offender.
With sequential lineups, witnesses must decide about each photo or subject before moving on to the next, leading them to use absolute judgment – that is, comparing each subject only to their memory of the offender.
Some research also concluded that the blind sequential method – where the lineup administrator does not know the identity of the suspect – produced fewer false IDs than simultaneous lineups in which the administrator knew who the suspect was because it avoided any suggestibility – inadvertent or otherwise – from the administrator.
Then an Illinois Pilot Program in 2003 in which the Illinois State Police conducted a yearlong examination of the blind sequential versus the simultaneous lineup rattled the research cage. Data collected from 700 photo and live lineups from urban, suburban and semi-rural Illinois police departments showed that blind sequential lineups had a higher rate of false IDs and a lower rate of “suspect picks” than the simultaneous lineup.
The Illinois program results have since been undercut with challenges based on flawed methodology but there is still disagreement with the research community. Roy S. Malpass, Ph.D., professor of psychology at the University of Texas at El Paso has said,