Authorities say they now have a motive for the first time in the Megan McDonald cold case from her death in 2003.

McDonald's ex-boyfriend, Edward Holley, was charged with her killing on Thursday. They say he owed 20-year-old McDonald money and was jealous after she broke up with him and started seeing someone else.

“I’m definitely not guilty. I love Megan with all my heart," Holley said.

Holley was always a person of interest, according to the police. McDonald was found dead from blunt force trauma in a field off Bowser Road after her family and friends reported her missing.

State police say new DNA technology and newly obtained evidence links Holley to the 2003 death in the Town of Wallkill.

“The monster who violently and senselessly took Megan’s life now has a name and a face," said McDonald's brother-in-law James Whalen.

Authorities have never given up on the case and in recent years ramped up efforts to get enough information to charge Holley. Holley has been charged with second-degree murder. He was already incarcerated at the Orange County Jail on unrelated charges at the time of his arrest, according to police.

Just last month – a new lead led police to a reservoir in Mount Hope where they say evidence was found.

“These men gave us hope. With them it was always a matter of when, not if this day would come," added McDonald's sister Karen Whalen.

Authorities concluded Holley killed McDonald in her car during a vicious attack and dumped her body on a wooded trail.

They say a second person was in the car when she was killed and that they’ve since died.

Holley is set to be back in court next week.