Reading the Mind to Determine Innocence

Focuses on brain fingerprinting, a technique that measures brain activity or inactivity following attempts to trigger memories. Importance of the technique in proving the innocence of a suspect; How the procedure is administered; How Terry Harrington, a suspect who has served 22 years in prison, might be freed by using the technique.

By W. Eric Martin, published March 1, 2001 - last reviewed on June 9, 2016


Terry Harrington has served 22 years for a murder he says he didn't commit, but he might be a free man soon thanks to new evidence admitted in a retrial last fall: his brain.

Lawrence Farwell, Ph.D., a psychiatrist with Brain Wave Science, a brain research laboratory in Fairfield, Iowa, has developed a technique called "brain fingerprinting" that measures brain activity--or inactivity--following attempts to trigger memories.

In the procedure, Farwell monitors the brain's electrical activity while the subject is exposed to words or pictures that may have significant meaning to him. A criminal suspect like Harrington, for example, might be asked to think about events surrounding the crime. Both real and false circumstances are displayed on a computer monitor while the suspect's brain activity is recorded.

"If the suspect recognizes the details of the crime, this indicates that he has a record of the crime stored in his brain--including things that only the perpetrator would know," says Farwell. But innocent people exhibit no special brain activity because they lack the context that would make a particular answer meaningful. According to Farwell, Harrington's brain showed no memory of the crime scene but did show memories of attending a rock concert with friends the same night, which matches Harrington's alibi.

Farwell's research on the technique, scheduled for publication in the Journal of Forensic Sciences, found that it determined with nearly 99% accuracy whether the six study subjects had participated in the event in question. And while further research is necessary, Farwell predicts the technique will be widely used in the future. "When you have a crime scene, fingerprints or DNA are available in only about one percent of cases," he says. "But the brain of the perpetrator is always there, planning, carrying out and recording the crime"

PHOTO (PHOTO (BLACK & WHITE): If memory were as exact as this mirror's reflection, techniques like "brain fingerprinting" would be unnecessary.