Reginald Thomas can't forget the " two big thumbprints" he saw pressed into his older sister Melissa's neck when he saw her body after her 1996 murder.
Using a person's unique physical traits like a thumbprint or iris to confirm identity may seem like the stuff of science fiction but it's becoming more and more common.
Some suggestions are that it would be better to use the print of a thumb so the thumbprint would be used instead of a fingerprint. Both are a possibility.
He then had to give written answers to two questions: in future, could he stop his illegal activities? “I can, ” he wrote, and put his thumbprint, in red ink, on his answer.