The father of a 13-year-old girl who police say was slain by a Virginia Tech student said he found out about his daughter's death on TV, and questioned whether the tragedy could have been avoided if he had been more a part of her life.

During an episode of "Dr. Phil" that aired Wednesday, David Lovell told host Phil McGraw that police have not explained a possible motive for Nicole Lovell's death. He said he had raised concerns about his daughter's online conversations with older men, but partially blames himself for not putting an end to it.

"If I would've been there, maybe she wouldn't have went looking for acceptance from older guys," said Lovell, who gripped a stuffed panda bear and wore a blue ribbon on his jacket in his daughter's memory throughout the hourlong episode. "There's regrets that I have that I'll never get over."

David Eisenhauer, 18, has been charged with abduction and first-degree murder. Another Virginia Tech student, 19-year-old Natalie Keepers, is charged with accessory before and after the fact and with illegally dumping Nicole's body just across the state line in North Carolina. Authorities say Nicole was stabbed, but have not provided clues as to a motive.

A neighbor told The Associated Press recently that Nicole told 8-year-old friends before she vanished from her mother's home that she planned to sneak out to meet her 18-year-old "boyfriend," a man she said was named David. A friend and classmate was quoted by The Washington Post as saying that Nicole had talked about running away and starting a family with Eisenhauer.

When shown a picture of Eisenhauer, David Lovell told MGraw that it's difficult to look at the man's face.

"I would like to get locked up in the same cell with him," he said. "I'm pretty sure I could get answers out of him. He took my little girl."

Lovell said authorities forgot to tell him before they told reporters that his missing daughter had been found dead. But he did not blame officials, saying it was "a screw-up" and that they apologized for the oversight.

Neither the spokesman for the Blacksburg Police Department nor an attorney for Keepers immediately responded to an email seeking comment on Wednesday. An attorney for David Eisenhauer said in an email this week that he is not commenting on the case.

David Lovell pledged to make it his mission to ensure that parents know the dangers of social media. He said he found out about his daughter's conversations with men online before Christmas and her phone was taken away, but she later got it back. He said he wishes he could have done more.

"I wasn't there for her when she needed me," he said, his voice quivering and tears in his eyes. "There's no way to roll back the time."