Parents: Accused Killer Changed After Iraq

Johnny Lee Williams, 24, sits in an Arizona jail, accused of abducting 19-year-old Wal-Mart clerk Megan Holden as she left work and killing her. A security camera captured Holden's abduction as a man believed to be Williams forces her into her pickup truck and drives off.

But those close to Williams say they are as shocked by the incident as anyone. A decorated Marine who served one tour in Operation Iraqi Freedom, Williams' family says he was changed by the war.

In an exclusive interview with "Good Morning America," his parents, Patricia and the Rev. John Williams, say their son came back from Iraq troubled and begging the military for mental treatment, which he never received.

Personality Changes After Iraq

"He is a different person since the war," said Patricia Williams. "There was a change in our son from growing up to be a happy-go-lucky person. He was not a violent person ... When he came back, he was different."

Patricia said her son was much quieter and had trouble sleeping. "He slept in his clothes. He had nightmares. ... He would ask friends to come over and just stay while he was going to sleep," she said.

To some observers, the changes in Williams' behavior sound like post-traumatic stress disorder.

Twenty percent of servicemen and women returning from Iraq say they suffer from post-traumatic stress disorder. Former Navy psychiatrist, Dr. Paul Regan, says most are not getting adequate help.

"The fact is that post-traumatic stress disorder is very real and Mother Nature is very cruel," said Regan.

Parents Looking for Answers

John Williams, a church pastor, said his son was deeply troubled about his time in Iraq and spoke of having to kill three people, including a child, while stationed there.

John Williams said he and his son prayed together. "I explained to him it was war," he said. "It was a duty he had ... I said, 'God will forgive you.' "

Williams, though, had been in trouble with the law before going to Iraq, including drug charges and a criminal trespassing charge. Despite that, his parents say violence was completely out of character for him.

Patricia and John Williams insist the person who committed Holden's murder is "not our son, is not the person we know him to be," and they are looking for answers from the military.

"Something happened to change our son; we want to know what it was and why," said Patricia. "Somebody had to see the difference. Why wasn't something done? We were notified of his promotions. We were notified by his commanding officer when he was in Iraq that his post had been changed ... Why weren't we notified he was having problems?"