Officials are investigating the death of condemned incarcerated person Alberto Martinez as a homicide.

On Thursday afternoon, at about 1:20 p.m., staff saw Tyler A. Lua strike Martinez, knocking him to the ground. Lua continued to hit Martinez and as Lua stepped away, Jorge D. Negrete-Larios and Luis J. Beltran began hitting Martinez. Staff stopped the assault using pepper spray and a baton strike. Martinez was taken to the prison treatment area and shortly after was pronounced dead. Officials said that Martinez had injuries consistent with a prisoner-manufactured weapon. Two such weapons were found at the scene of the assault. 

Prison officials limited movement on the yard where the attack occurred and the three suspects were placed in restricted housing pending the investigation. Martinez, 46, was received at Calipatria Prison in 2010 out of Orange County. He was placed on condemned status for First Degree murder.