A skull found in the desert last weekend was identified Tuesday as that of 19-year-old slaying victim Daniel Lee Davis Smith of Twentynine Palms.
Two former Marines and a 17-year-old youth are in custody in connection with the killing.
San Bernardino County sheriff's deputies began an investigation Dec. 31, acting on a tip. On Jan. 3, some of Smith's remains were discovered in the desert near Twentynine Palms, but they could not be positively identified.
The same day, officials arrested Allen K. Patterson, 23, a former Marine from New York, on suspicion of murder.
On Jan. 17, they arrested another former Marine, Justin Van Meter, 22, of Twentynine Palms, along with a 17-year-old whose name has not been released.
Over the weekend, a hiker found the skull.
Investigators have said that Smith may have been killed because the suspects believed he was telling authorities about drug dealing. But authorities said Smith was not an informant.
Coroner's officials, who identified Smith, did not reveal the cause of death.