Firefighters and deputies responded to a home in the 400 block of Jeanne Court in Newbury Park around 8 p.m. Thursday, according to the Ventura County Sheriff's Office.
The teenager was found with blunt force trauma to the head, sheriff's officials said. He died on his way to a hospital.
The suspect was later taken into custody on the Newbury Park High School football field. He was naked at the time of the arrest.
Further details surrounding what led up to the killing were not immediately released, but authorities said the suspect and victim knew each other.