contacted security because of his top-secret clearance. An investigation revealed the whole scam. Wallace got an annulment. Boyer got a divorce, which was when she received the house and Overton began poisoning her coffee.

Years went by and Overton married again. But all was not well in this marriage either. He suspected Janet was cheating on him, and gave her cyanide to make her sick. But this time, instead of just becoming ill, she died.

THE EVIDENCE

After Overton's arrest, a search warrant was executed. Among other things, police confiscated numerous floppy disks. One of the disks contained the remains of his personal diary, which would turn out to be the key piece of evidence in the case. On June 9, 1992, the trial began.

"All the clusters on the disk were used," said Joe Enders, who testified at the trial as a computer evidence expert. "It appeared that he tried to copy his personal diary from the hard drive onto a floppy, but the diary wouldn't fit on the disk, so he probably got a message that there was not sufficient space on the disk to hold the diary. He must have replaced the disk with a new one, which he probably hid or destroyed," Enders explained. But what the defendant didn't know was something Enders had learned while studying a relatively new area of law enforcement -- known as forensic computer science -- at the Federal Law Enforcement Training Center (FLETC) in 1989.

While there was no indication of a file on the disk, Enders knew that when someone tries to copy something onto a disk, the computer writes one cluster after another. "If there isn't enough space to copy the entire file, the machine tells the user there's not enough space. It goes back and deletes the file entry in the directory, but leaves all the information it had already written to the disk. So except for the very end of the diary, which there wasn't space for, all the information was still on there."

But even with this key piece of evidence, prosecutors were still up against a crafty individual who did not want to go to jail. "During the trial he got up and testified and either had a heart attack or feigned a heart attack when he came off the stand, so they stopped the trial," said Enders. "While he was allegedly recovering, his attorney had a mental breakdown. The trial was delayed for such along period of time, the judge declared a mistrial."

THE SECOND TRIAL

At the second trial, which began March 28, 1995, lawyers for the prosecution finally had a chance to present their computer evidence. While the defendant testified that he and Janet had a happy and problem-free marriage, prosecutors presented pieces of the diary they had recovered from the disk that proved otherwise.

"While he didn't spell out that he was going to kill his wife, the diary did reveal his state of mind, and that there were problems between them and it wasn't a lovely marriage as he was pretending," said Enders.

Overton was subsequently convicted of the murder of his third wife and, on Sept. 1, 1995, was sentenced to life in prison without the possibility of parole.

LESSONS FOR LAW ENFORCEMENT

Although computers now play a larger role in the daily life of many Americans, Enders said most law enforcement agencies are unaware of the existence of computer evidence or the value of such information.

"I think in general that a lot of evidence goes untouched or gets contaminated," he said. "It's a big problem that exists with law enforcement. If they do find evidence in a computer, a lot of times they'll take people that know computer fundamentals but don't know anything about processing computer evidence. They don't realize