YOU know the routine. Nine shifty characters shuffle into a room and stand in
a row waiting for a witness to point the finger. But using live identity parades
to spot criminals is notoriously unreliable.
鈥淭he courts are locking up someone based on wrongful identity at least every
working day,鈥� estimates psychologist Tim Valentine of Goldsmiths College,
University of London. So Valentine has been working on what he says is a fairer
method鈥攙ideo line-ups. Not only do they prevent so many cases of mistaken
identity, he says, but they would also save the police money and reduce the
stress on witnesses and suspects.
To compare the fairness of live and video line-ups, Valentine recreated
line-ups from actual cases. He gave mock witnesses a physical description of a
suspect, and then showed them either a video line-up or still pictures from a
live line-up. This reflects the worst-case scenario, where a witness remembers
the description they gave the police, but has no real memory of the actual
culprit.
Advertisement
In this situation, a witness who can鈥檛 remember the incident clearly should
only be able to guess at the suspect. And if the live line-up is completely
fair, all nine individuals should match the physical description of the suspect
so well that the forgetful witness is equally likely to pick any one of
them.
But Valentine found that, on average, mock witnesses were about twice as
likely to pick someone in the live line-up than in the video line-up. He thinks
this is because live line-ups have such a varied range of suspects that the
witness ends up plumping for anybody that matches the physical description.
Video line-ups are fairer because individuals who closely match the suspect
can be selected from a large library. Witnesses are more likely to tap into
their memory of who they saw at the crime scene instead of relying on a physical
description.
鈥淎 video parade is fairer all the way around,鈥� says Peter Burton, head of the
imaging unit for West Yorkshire Police. 鈥淚t鈥檚 fairer to the witness, who doesn鈥檛
have to feel intimidated by having to face the perpetrator of the crime, and
it鈥檚 fairer for the suspects themselves who find conducting a live line-up a
very traumatic experience.鈥� And the police save money, Burton says, because they
don鈥檛 have to pay volunteers and waste time searching for suspect
look-alikes.
A spokeswoman for Britain鈥檚 Home Office says they are considering revising
the law to encourage the use of video line-ups. 鈥淲e agree they鈥檙e more efficient
and they鈥檙e quicker,鈥� she says. Currently, police have to use a live identity
parade as a first option.