Brain fingerprints under scrutiny
By Becky McCall in Seattle

The technique relies on electrical signals in the brain
A controversial technique for identifying a criminal mind using
involuntary brainwaves that could reveal guilt or innocence is about
to take centre stage in a last-chance court appeal against a death-
row conviction in the US.

The technique, called "brain fingerprinting", has already been tested
by the FBI and has now become part of the key evidence to overturn
the murder conviction of Jimmy Ray Slaughter who is facing execution
in Oklahoma.

Brain Fingerprinting, developed by Dr Larry Farwell, chief scientist
and founder of Brain Fingerprinting Laboratories, is a method of
reading the brain's involuntary electrical activity in response to a
subject being shown certain images relating to a crime.

Unlike the polygraph or lie detector to which it is often compared,
the accuracy of this technology lies in its ability to pick up the
electrical signal, known as a p300 wave, before the suspect has time
to affect the output.

"It is highly scientific, brain fingerprinting doesn't have anything
to do with the emotions, whether a person is sweating or not; it
simply detects scientifically if that information is stored in the
brain," says Dr Farwell.

"It doesn't depend upon the subjective interpretation of the person
conducting the test. The computer monitors the information and comes
up with information present or information absent."

brain fingerprinting doesn't have anything to do with the emotions,
whether a person is sweating or not; it simply detects scientifically
if that information is stored in the brain

Dr Larry Farwell
Brain fingerprinting is admissible in court for use in identifying or
exonerating individuals in the US.

Maximum security

A few days ago Dr Farwell ran the test on Jimmy Ray Slaughter at the
maximum security state prison in Oklahoma.

A jury convicted Slaughter of shooting, stabbing and mutilating his
former girlfriend, Melody Wuertz, and of shooting to death their
eleven-month old-daughter, Jessica.

The crimes for which he is sentenced to death took place in a house
that he is very familiar with. The results were revealing.

"Jimmy Ray Slaughter did not know where in the house the murder took
place; he didn't know where the mother's body was lying or what was
on her clothing at the time of death - a salient fact in the case,"
says Dr Farwell.

During the test, the suspect wears a headband equipped with sensors
to measure activity in response to recognition of an image relating
to the crime - for example, a murder weapon or possibly a code word
in the case of a spy.


Dr Farwell claims some tests were 100% accurate
"In research with the FBI, we presented words and phrases that only
an FBI agent would know and we could tell by the brain responses who
was an FBI agent and who was not; we could do that with 100%
accuracy," says Dr Farwell.

Brain Fingerprinting has profound implications for the criminal
justice system.

Any decision relies on more than just the outcome of a forensic test
such as brain fingerprinting. However, in the light of these
findings, the case for appeal hopes that Slaughter will either be
granted a pardon, clemency or a retrial.

Critics of brain fingerprinting believe it needs far more refinement
before its use becomes widespread and cases are won and lost on its
evidence.

Needless to say, Dr Farwell disagrees.

"What I can say definitively from a scientific standpoint, is that
Jimmy Ray Slaughter's brain does not contain a record of some of the
most salient details about the murder for which he's been convicted
and sentenced to death," says Dr Farwell.


http://news.bbc.co.uk/2/hi/science/nature/3495433.stm