COEUR D'ALENE, Idaho -

The teen suspected of killing his dad and brother recounted to authorities after his arrest how he idolized a violent character from the video game "Grand Theft Auto V," and had contemplated and mentally prepared for his family's murders for months.

Monday night police responded to a shooting in the 1300 block of North 1st Street in Coeur d'Alene. The person who called 911 was Eldon Samuel III, 14, who told police he had shot his dad and brother. When officers arrived he answered the door, the telephone still held up to his ear and covered in blood.

Eldon Samuel III told police that his dad, Eldon Samuel Jr., had been ranting about zombies that evening in the front yard and even fired a shot into their home. Later, while inside, he started hitting and pushing his son. The teen said that is when he shot his dad in the gut with a .45 caliber handgun.

His dad started crawling to his younger son's room and that's when his 14-year-old son stood over him, and shot him twice in the face and once in the head.

During that time, 13-year-old Johnathan Samuel had been hiding under the bed. Police reports say Eldon Samuel III grabbed a shotgun, and shot his brother four times and then stabbed him with a large knife before ultimately returning with a machete to finish the job. Eldon Samuel III estimated he struck his brother Jonathan with the machete around 30 times.

During a police interview Eldon Samuel III said he only 'slightly' regretted killing his father but blamed his brother for his anger and frustration. Their murders were something he said he was mentally preparing for the last eight months.

Dr. Paul Domitor, a retired psychologist, has worked with teens in Eldon Samuel III's position before. He said there are several early warning signs to deteriorating mental health.

"Torturing animals, bed wetting and fire setting, as young children," Domitor said.

Court records show Eldon Samuel III's grandparents admitted he had tortured animals as a child.

Domitor also keyed in on Eldon Samuel III's mention of "Grand Theft Auto V" and his idolization of Trevor, one of the more violent characters in the game. Domitor said often times video games will create a disconnect between the gamer and reality.

"What you have is your own little universe in which you have all this power and violence is seen as a solution," Domitor said.

Domitor said parents with concerns about a child should watch for signs of difficulty adapting in school, social isolation and a preoccupation with fantasy. These are signs a professional mental evaluation may be needed.

"The therapist needs to be able to explain to the parent about what they're doing and what the expected outcome is and something about the expected time frame," Domitor said.

Strong family participation and continued mental care can help a disturbed child or teen, "but adaptation in the world and success in the world is the best antidote in the world for these kids," Domitor added.

In court documents Eldon Samuel III claimed his father often beat him. If that abuse is substantiated in court it could play a role in his sentencing, if he is found guilty on the two counts of first-degree murder he's now facing -- as an adult -- for the murders of his father and brother.