ATLANTA -- In the next 30 minutes, more than 50 women will be beaten, raped, or murdered by a loved one, according to statistics. And for teenage girls, this year is ranking among the deadliest.

"You can never tell what's on a man's mind which would cause them to commit such violent acts," said convicted murderer Jason Pierce, who spoke with CBS 46’s Wendy Saltzman from prison.

Pierce pleaded guilty to killing Patrice Lassiter and Monique Brown, two students who were living with his former girlfriend at Clark-Atlanta University. Lassiter and Brown were caught in the crossfire when Pierce attempted to gun down Shuane Allen, 18, in 1999. Pierce shot Allen in the face, but she lived to testify against him at trial.

"When a person is emotionally unstable, these people do irrational things," Pierce said. "Some people could snap."

Even though Pierce pleaded guilty to murder, he has not accepted responsibility. When Saltzman asked if he felt responsible for the murders, Pierce responded, "I can not answer that."

Fulton County District Attorney Paul Howard said is it not uncommon for a perpetrator to deny blame when a relationship turns deadly.

"Even from his perspective of being on trial for her death, he still held her responsible, responsible for the breakup," Howard said.

The district attorney has started a campaign against teen relationship violence, because Howard said crimes of passion have become too common, too violent, and too deadly. "The victims are getting younger and younger," he warned.

Howard said the indicators of this obsessive behavior are different than law enforcement previously thought. Often, the perpetrators are successful, well-liked, and have never had a brush with crime, Howard said. He advised that the factors people should look for are obsessive behavior like constant texting, stalking, and the lack of ability to let go when a relationship ends.

"He didn't just take my daughter, he shot her co-worker out of the way," Jessica Riden said about her daughter's killer, Damien Harris.

Riden’s daughter, Kendra Mason, was 17 when she and a co-worker were gunned down in the parking lot of Greenbriar Mall last year.

"She made the decision he was not who she wanted in her life two days before he killed her," Riden said.

Riden said the warning signs that something might go wrong only started a few days before Harris stalked Kendra and took her life. Harris visited the house unannounced, and called her daughter dozens of times in a matter of minutes.

"I had noticed that her phone kept ringing, kept ringing and I looked at it, and it was him," Riden said. "Before that, there were no signs. He was just a young boy who I thought needed guidance."