Convicted murderer David Laffer broke a decade of silence to talk to the Turn To Tara team about his regrets, prison life, gun violence, the accessibility of guns - and the five minutes he wishes he could take back.

He shared his story of one of the most gruesome crime scenes in Long Island history in the hope of preventing someone else from following his path.

Laffer is serving five life sentences without the possibility of parole for his crime. 

On June 19, 2001, Laffer walked into a Long Island pharmacy and opened fire with his .45 caliber pistol.

Two employees and two customers were killed in the shooting.

"I realized after that first shot went off, that I had just taken a life," he says. "I realized after that shot went off ... my life has now entirely changed. Once that first shot went off, that was it mentally just a switch, sort of triggered." What puzzled some was that the former U.S. Army soldier didn't fit the profile of a cold-blooded killer.

"(I had a) great childhood, our parents weren't abusers, weren't drug addicts, very typical suburban upbringing," he says. 

After graduating high school, Laffer enlisted in the Army Reserve and even went to intelligence school.  He says all his dreams were dashed after he was injured and became addicted to painkillers in 2010. 

He says his only intent that Father's Day morning was to steal prescription pills from Haven's Drugs after realizing there were no more doctors to go to and no more prescriptions to fill. 

"I remember their faces. They weren't expecting a shot. So, there was no look of fear or surprise," he says.  He said he never thought he would get away with the crime, but that "the withdrawal was all encompassing. It outweighed everything, anything. Addiction is not a good thing.

"His youngest victim was 17-year-old Jennifer Mejia, who wanted to be a doctor. 

"I'm sure that she begged for her life," says her sister, Lesly Gonzalez. "I hope she didn't suffer. She wasn't going to hurt anybody...he could have easily left her. She was a kid."

If given the opportunity, Laffer says there is a lot he would say to the family of the victims. 

"I pray for them every night - Raymond, Jennifer, Bryon and Jamie ... I think about them every day," he says. "I'm not the evil monster that the media made me out to be."

To to catch the full interview, tune in to News 12 Tuesday night for "Triggered."