Officials at Calipatria State Prison are investigating the death of a 21-year ld inmate as a homicide.

At about 3:00 p.m. Friday , correctional officers responded to the Facility C maximum security yard when inmates Robert A. Garcia and Brian Figueroa attacked Martinez. Martinez suffered numerous puncture wounds to his chest and back. He was treated at the prison medical facility and then transferred to a local hospital where he died.

Garcia , 24 , is from Los Angeles County and was sentenced to 50 years to life for first-degree murder and several related charges. Figueroa , 26 , is also from Los Angeles County and is serving a life sentence for murder.

Martinez , was serving a 24-year-to-life sentence for attempted first-degree murder with enhancements including street gang activity. 

Both Figueroa and Garcia have been moved to the Administrative Segregation Unit pending investigation. An inmate-made weapon was recovered. The Imperial County District Attorney's Office is assisting prison officials with the investigation.