Military authorities say the sailor found dead on the Camp Pendleton Marine Base was shot numerous times and a fire was set in an apparent effort to cover up the crime.
There's no evidence as of yet the killing was a hate crime, a Navy spokesman said. The victim was openly gay.
A suspect is in military custody in connection with the suspected murder of Seaman August Provost of Houston, 29. He was found about 3:30 a.m. Tuesday on the western edge of the base, a spokesman said.
The case has led to calls by gay activists for a thorough investigation to determine whether Provost was killed of his sexual orientation. Relatives have told reporters he had complained to them about being harassed because he was gay.
The new information was presented by Navy officials during a briefing Thursday afternoon in San Diego.
The Naval Criminal Investigative Service is investigating Provost's death. He was assigned to Assault Craft Unit 5, a hovercraft unit.
Two "persons of interest'' were initially detained in the case, but one has since been released, said Capt. Matt Brown, director of public affairs for Navy Region Southwest.
Despite the gunshot wounds, a precise cause of death is not being released pending more tests.
Brown said the case has stunned everyone involved in the man's unit.
"I can tell you right now I've spoken with the commanding officer of ACU5," he said. "He and his entire staff are working through a very intensive grieving process right now."
For more info: Pendleton sailor, reputedly gay, found dead on base | Navy: No sign sailor's slaying was hate crime