After two years on the run, U.S. Marshals arrested Aeriontae McClendon on Monday on suspicion of murdering 16-year-old Jerry Orisme in November of 2011.
Marshals tracked down McClendon on 8th Street in Riviera Beach.
They say he was hiding out with an AK-47 in the house.
Riviera Beach police say McClendon shot and killed the teen with a rifle.
U.S. Marshals moved in on the house where he was hiding on Monday morning.
"He was definitely caught off guard when we showed up, and thank goodness he was. There were three guns in the house waiting for us and they could have done us harm. Those rifles go right through our vest," said Manny Puri with the U.S. Marshals Service.
The Marshals assisted Riviera Beach police as part of the Florida Regional Fugitive Task Force.
The investigation is ongoing.