DNA sample forces guilty plea in '89 Sumter killing

SUMTER, S.C. - A man has pleaded guilty to murder in the killing of a Sumter woman 17 years ago after investigators were able to link his DNA to the crime scene thanks to his brother, who was in prison.

Tony Oliveo Mack, 41, of Fayetteville, N.C., was sentenced to 30 years in prison Thursday after accepting a plea bargain from prosecutors.

Joyce Robinson, 29, was found dead in her Sumter home in April 1989. Authorities said the killer had nearly severed her head with a knife. It was a violent struggle as Robinson had numerous defensive stab wounds on her body, Sumter Police Department attorney Martha Horne said.

"This is probably one of the most severe crime scenes I've ever seen," Horne said.

DNA from the killer was found at the scene and authorities spent more than a decade checking it time after time against other samples, police said.

Finally about three years ago, scientific advances allowed investigators to figure out the DNA had some characteristics in common with Mack's brother, who was in prison, Horne said.

They got a blood sample from Mack, and it matched. The chances of the killer being someone other than Mack are one in 66 quadrillion, State Law Enforcement Division agent David McClure said in court.

Mack's fingerprints were also found on a purse in Robinson's bedroom and on her bathroom sink, Horne said.

Mack said little in court Thursday, holding out his hands and shaking his head when the judge asked him if there was anything he would like to say prior to entering his plea.

Mack had no family in court, and prosecutor Kelly Jackson said Robinson's brother did not want to attend the hearing. "He asked us to notify him once this was over," Jackson said.

A motive for the killing was not given.

Robinson was buried in her wedding dress. She was engaged to a state trooper at the time of her death.