The mother of the man charged with killing an Auburn University student said her son was an Iraq war veteran who was changed after his service, and offered an apology to the freshman's family.

Catherine Williams, the mother of suspect Courtney Lockhart, made the apology to Lauren Burk's family in an interview with Columbus, Ga., television station WTVM.

"I am sorry that Courtney did that. ... First let me say I'm sorry to the Burk family for Courtney taking, taking their child. ... My heart goes out to her family," Williams said in the tearful interview.

But she also said her son did not confess anything to her.

The 23-year-old Lockhart has been charged with capital murder in the death of an 18-year-old Auburn University student and could face the death penalty if convicted.

Lockhart also faces charges of kidnapping, robbery and attempted rape, Auburn Assistant Police Chief Thomas Dawson said at a news conference. He affirmed that authorities have strong evidence to prove that Lockhart killed Lauren Burk, a freshman at Auburn University.

Dawson declined to identify the evidence or potential motives for the crimes, and he wouldn't say conclusively whether Burk had been targeted or was the victim of a random crime.

"I don’t believe he targeted her for that long, if he targeted her at all," Dawson said.

• Click here to see photos.

Click here to view video.

Burk of Marietta, Ga., was found shot and wounded Tuesday night on a state highway a few miles off campus. She died later at a hospital. At about the same time, her car was found on campus engulfed in flames.

Auburn police and numerous other state and local agencies formed a task force to investigate the killing, and they identified Lockhart as the prime suspect through a photograph obtained Wednesday, Dawson said, though he wouldn't say how the photo was obtained.

Lockhart was arrested Friday in Phenix City, Ala., about 30 miles from Auburn near the Georgia border. He tried to flee Phenix City police by car after being pulled over Friday. Lockhart, is in custody with bail set at $250,000, Dawson said.

Burk's killing, which shocked the Auburn University campus as well as the greater Auburn community, occurred the day before the mysterious killing of another female college student, in North Carolina.

No one had been arrested as of Sunday in the killing of Eve Carson, a senior at University of North Carolina in Chapel Hill, though police released a surveillance photo of a person of interest at a news conference held almost simultaneously with the news event in Auburn.

Authorities say connections between the two killings are unlikely.

“We have been in contact with Auburn authorities there. ... We don’t believe the cases are related," Chapel Hill Police Chief Brian Curran said.

Click here for more on the Carson killing investigation.

FOX News' David Paulsen and The Associated Press contributed to this report.