LAS VEGAS, NV -- A teenage has pleaded not guilty to two murder charges stemming from the deaths of his 6-year old cousin and later his cellmate.
Carl Guilford is accused of suffocating his 6-year-old cousin and, after his arrest, beating and stabbing to death his cellmate.
Guilford was arrested May 26 after being accused of suffocating his cousin with a comforter and was booked into the Clark County Detention Center.
According to his arrest report, Guilford was trying to quiet the boy so he wouldn't wake the boy's mother.
Guilford told Las Vegas police he heard the devil's voice tell him "well done" after he killed the boy.
Guilford's mother told investigators her son is bipolar and talked openly with family members about angels and demons and had mentioned "making sacrifices."
Two months after his arrest guards found Guilford's cellmate unconscious and wounded during an early morning bed check at the Clark County Detention Center, and he was pronounced dead at the scene, police said.
"The suspect physically battered the deceased inmate and stabbed him with a pencil," police said in a statement.
Police spokesman Bill Cassell said pencils were among items allowed in the jail.