A family friend told Channel 2’s Sophia Choi that the teen was angry that he was told to stop playing the game Halo. Investigators said he used a 34- to 36-inch sword to cut his grandmother, 55-year-old Laura Prince, in the arm and to kill his great-grandmother, 77-year-old Mary Joan Gibbs, on Monday.

The attack marks the third time deputies have encountered the teen.

Sheriff Phil Miller said on two previous occasions, the teen was sent to a hospital to be mentally evaluated and then turned over to Juvenile Justice. But both times, Miller says, the boy was released, despite his violent history.

"It just seems to me that somebody may not be doing what they could do, or we may be dropping the ball somewhere in the system," Miller told Choi.

Miller said someone else was recently killed by a mentally ill person who slipped through the cracks. On July 22, a deputy shot a man described as schizophrenic after he used a knife to kill a man, deputies said.

Miller said the suspect’s mother “cried out for help many, many times to many, many different places and didn’t really get it."

There have been two killings in Douglas County this year, both involving people with a history of violence and mental illness, Miller said.

"I want to make sure that these people who are crying out for help get it," Miller said.