A Caldwell County man will spend the rest of his life in prison after he pleaded guilty Monday to killing a local teenager and her friend. 

Prosecutors said it came down to money Justin Hester owed the 19-year-old he had once dated. Investigators said they were able to quickly identify those responsible by secretly recording a phone conversation and retrieving text messages.

Fighting back tears, family members of Harley Carter and Kevin Shatley stood feet away from the man responsible for their murders.

"The choices you made to murder Kevin and Harley changed our lives forever,” said Toni Shatley, the victim's mother. “I go over and over in my mind, ‘Why, why?’ Why is there no answer from you?"

The victims were shot to death in June 2010. Prosecutors said the plan called for pushing the vehicle into Lake Rhodhiss but when it got stuck in the mud, it was set on fire with the victims inside.

Two men are accused of helping Hester after the murder. They are both charged with accessory after the fact.

“It was a significant fire. Almost the entire interior had been consumed,” said Assistant District Attorney Eric Bellas. “When they began searching the vehicle, they became concerned there may be one or more people inside."

Prosecutors described some of the evidence in the case, including the first clue they found: Kevin Shatley's ring near the charred remains.

Hester had nothing to say to family members after pleading guilty to two counts of first-degree murder. 

Family members of the victims said they have struggled with forgiveness.

“I know we have to forgive him and pray for him,” said Marie Teague, the victim's aunt. “But there is no way any of us can forget."

Prosecutors said the other two men arrested in the case remain in jail, waiting for their day in court.