Treasure Coast Newspapers reports 28-year-old Trayvon Jackson pleaded no contest yesterday to second-degree murder as part of an agreement with prosecutors.
His sentencing is scheduled for December 21.
He had been facing a first-degree murder charge and minimum life sentence.
Authorities say 18-year-old Dylan McKelvey was found dead in an Indiantown field in March 2014. He had multiple gunshot wounds to his head and body.
Authorities say the teen had been living "the gangster life."
At the time of his death, detectives reported McKelvey had gold teeth and the tattoos of a Stuart-based gang on his hands.