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Barton Linked To '93 Murder

This is not the first time that Mark Barton, who killed 13 people in Atlanta Thursday, has been linked to violent deaths.

In 1993 Barton's first wife, Debra Spivey Barton, 36, and her mother, Eloise Powell Spivey, 59, were found bludgeoned to death at Riverside Campground on Weiss Lake in northeast Alabama. They had been staying in a camper without Barton and the camper showed no signs of forced entry.

The killer took two rings, but ignored other jewelry and an envelope containing $600. Mrs. Spivey's .32-caliber revolver lay on the kitchen counter.

Barton was considered the prime suspect in that case but was never charged with the crime.

There were good reasons why Barton was never charged for the 1993 murders, Mike O'Dell, formerly the assistant district attorney who investigated those deaths and now district attorney for Dekalb and Cherokee counties, told CBS This Morning, speaking from Ft. Payne, Ala.

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"We had a great deal of circumstantial evidence and we developed strong hunches about his guilt, but we had no physical evidence that we could use that would tie him to the scene," explained O'Dell. "Despite our feelings and what we believe very strongly about his guilt, we were not able to take him to trial."

Barton's alibi at the time was that he was at home baby sitting his two small children. They lived in Atlanta, and his wife and mother-in-law were spending Labor Day weekend at the campground.

"We learned pretty quickly there was a $600,000 life insurance policy taken out on his wife, about four days prior to her death," O'Dell continued.

"That was probably the first red flag that went up in this case. We also had information that he had been maybe estranged from his wife. We didn't know if they were on the verge of separation. But we did know that there appeared to be another woman," O'Dell said.

"That was confirmed several months later, when he married the wife that he recently killed," he said.

Barton collected on the policy about a year later after threatening to sue the insurer. He used the money for his day trading and lost $300,000 of it last year, according to Maj. Phil Miller, of the sheriff's department in Douglas County, Ga.

O'Dell said he was sickened when he heard that Barton was responsible for the Atlanta shootings: "The shock initially of seeing so many people being senselessly murdered. Seeing his picture and putting together he was the only suspect in our homicide here in the 1993 slayings was a very shocking and sickening feeling, frankly."

In his suicide note, Barton denied killing his first wife and her mother.