Can we base a conviction on one palm print? In August of 1984, a double sexual assault took place in West Norwood, south London, UK. A teenager assaulted a woman in her home and forced her flatmate to join in the abuse. The teenager wore a balaclava and used an iron bar to force the woman and her male flatmate to undress. He then forced them into sexual situations and abused both, before raping the woman twice, ransacking the home and escaping through the bedroom window, Southwark crown court was told.
Robert Clarke (now 42 but 16 at the time of the alleged crime) was arrested last September 2009 when Scotland Yard’s cold case rape unit reopened the file and found a match between his palm print and that of one left on a windowsill in the flat. Clarke denies two counts of rape, two of indecent assault, one of aggravated burglary, one of incitement to commit indecent assault and one of false imprisonment.
“This is a case that rests on a single strand of evidence, which is a palm print of the defendant,” Lisa Wilding, prosecuting, told the court. “Your role in this case is to decide whether that palm print was left by the man who had just raped and burgled [the pair] or whether there is some innocent explanation that we don’t know of yet.”
I have not been able to find out what other evidence the prosecution has in this case against Clarke. The single palm print might be all they needed to complete the case. However, if it is the only piece of evidence we would have to be extremely careful. We are obligated to consider the alternative explanation for the facts and not doing so could result in tragedy. And, mistakes in latent print identification have been made before.
The case of Brandon Mayfield comes to mind. Mayfield, an Oregon attorney and Muslim convert was held for two weeks as a material witness in the Madrid train bombing of March 11, 2004, a terrorist attack in which 191 people were killed. Mayfield, who claimed not to have left the United States in ten years and did not have a passport, was implicated in this attack almost solely on the basis of a latent fingerprint found on a bag in Madrid containing detonators and explosives in the aftermath of the bombing.
Federal Bureau of Investigation (FBI) Senior Fingerprint Examiner Terry Green identified Mayfield as the source of the latent print. A few weeks later, the FBI retracted the identification altogether and issued a rare apology to Mayfield. The Spanish National Police had attributed the latent print to Ouhnane Daoud, an Algerian national living in Spain.
Sadly, Mayfield is not the only one whose arrest was based on one palm or fingerprint. This report will tell you of the error rate in latent fingerprint identification. As for the Clarke case, this is definitely one to follow!
UPDATE: Clarke was convicted March 2011.