A 14-year-old boy accused of shooting to death his family at ABC newsman Sam Donaldson's (search) New Mexico ranch denied the charges in children's court Friday.

Cody Posey (search) was charged with three counts of murder and four counts of tampering with evidence in the slayings Monday of his father, who managed Donaldson's ranch, his stepmother and his stepsister. He told authorities his father regularly abused him.

"I suspect there's going to be a lot of questions as to why people ignored the signs that should have told them we had a young man desperately fighting for his sanity and help," said his attorney, Gary Mitchell.

A judge granted District Attorney Scot Key 30 days to consider whether to prosecute Posey as an adult. Key said the boy could get up to 30 years in prison if tried and convicted as an adult.

The judge also approved the appointment of an aunt on his late mother's side of the family as Posey's guardian. However, he will remain in custody at a juvenile detention center in Albuquerque.

Posey's mother was killed four years ago in a car accident.

According to court papers, Posey told sheriffs his father often abused him and on Monday slapped him across the face for not cleaning horse stalls fast enough. He then allegedly shot to death his father, Delbert Paul Posey (search), stepmother Tryone Posey and 14-year-old stepsister Mary Lee Schmid.

Donaldson came across the crime scene Tuesday, and deputies found the bodies near their home at Donaldson's Chavez Canyon Ranch (search).

Donaldson said that he never witnessed Delbert Paul Posey abuse Cody.

But the father of two of Cody's friends, Faustino Salcido, said the abuse was well-known to his sons and to others in the community.