Man on death row for 1999 slaying now linked by DNA to another woman's murder that same month

A man on death row for the 1999 slaying of a young Texas woman has now been linked by DNA to the murder of a 19-year-old in Louisiana who was killed that same month, authorities said.

Kassie Federer, 19, was shot dead at a Baton Rouge apartment on the afternoon of Sept. 13, 1999 -- but no arrest was ever made, according to Baton Rouge Police.

Until this week, when an arrest warrant was issued for Travis Green -- now 49 and on death row at a prison in West Livingston, Texas -- after DNA linked him to the Federer crime scene, the Baton Rouge Police Department said Tuesday.

Green is on death row for the unrelated murder of 19-year-old Kristin Loesch, who was killed in Houston on Sept. 2, 1999, the Houston Chronicle reported.

The murder of Loesch was just 11 days before Federer was shot dead in Baton Rouge, police said.

On Sept. 10, 1999, Green had been interviewed about the Houston murder but was released by Houston authorities, according to the Baton Rouge police arrest warrant affidavit.

Green was then arrested on Sept. 16, 1999 for the Houston killing, Baton Rouge Police spokesman Sgt. Don Coppola Jr. told ABC News.

Meanwhile, years went by in Federer's case, despite evidence including a glove left in the apartment with a DNA profile on the inside, police said.

The evidence was analyzed by the state police DNA unit in 2002 and then again in 2014, Louisiana State Police Sgt. Jared Sandifer told ABC News. The DNA profile was entered into CODIS -- which stands for the Combined DNA Index System, allowing federal, state, and local labs to compare DNA profiles electronically -- but with no result, he said.

Then this August, "with the growing size of the National CODIS Database which has reached an estimated 17 million DNA profiles," the FBI "modified its searching parameters" "to more effectively search DNA profiles," Sandifer told ABC News via email. "This change in search parameters resulted in the CODIS hit in the 1999 case."

On Oct. 3, police obtained a DNA swab from Green, Coppola said, and on Oct. 11 state police confirmed it was a match to the crime scene.

Baton Rouge Police on Tuesday issued an arrest warrant for Green for first-degree murder and aggravated burglary, police said.

Though 19 years have gone by, Federer's father is grateful for the detectives "who didn't give up the search."

Warren Federer told ABC News his daughter was a psychology student at LSU when she was killed. she wanted to work with children.

“Right now I'm still in a numb stage,” he said.

When he got the phone call yesterday he was "shocked" and elated. "All kind of emotions just turned into one. It's something you can’t describe."

Green is also believed to be connected to the 1988 killing of an 82-year-old woman in her Houston home, the Houston Chronicle reported in 2007.

Green has no scheduled execution date, according to the Texas Department of Criminal Justice.

Robert Hurst, spokesman for the Texas Department of Criminal Justice, declined to comment further.