It's not only a fingerprint which can link a killer to a crime; a shoe print can be just as telling. Armed with little else, police hoped the shoe impressions found at a Lansing, Michigan crime scene would put their investigation back on track.
A woman is found dead. A man's version of events was at variance with the evidence, so investigators turned to forensic science, hoping to determine if this was a botched robbery, or cold-blooded murder.
After a married couple decided to escape the cold of winter with a vacation in Key West, the wife went missing and police searched the island without finding any evidence. Then two important pieces of video surfaced.
A mother of two children is found dead near suicide notes and a pistol. At first it is assumed to be a suicide, but when police learn she had nearly been killed in a fire three years earlier, new suspicions are raised.
Investigators have to reassemble a computer disk that has been cut to pieces with shears, in order to determine the guilt or innocence of an Air Force serviceman suspected of brutally murdering his wife.
In 1984, California was riddled with 10 arson fires in three weeks. When some evidence points to other fires further up north, the investigation widens and continues until a fingerprint is finally found.