New Mexico authorities announced on Tuesday that a 15-year-old boy who killed his family with several weapons including an AR-15 military-style assault rifle enjoyed playing "violent" video games and had planned to go to a local Walmart to shoot random people.

Bernalillo County Sheriff Dan Houston told reporters at a press conference that Nehemiah Griego eventually admitted to the murders of his mother, father and three siblings after initially saying that he had come home to find them dead, according to KRQE.