Relatives of a New Mexico teen facing charges in the slayings of his parents and three younger siblings said Tuesday they are refusing to give up on the boy and are vowing to support him as his case moves through the justice system.

Nehemiah Griego's family members told The Associated Press in an interview that they are heartbroken over the tragedy and that there were never any signs that something like this would happen.

They described the 15-year-old as a normal teenager who was close to his family, loved wrestling with his father and brother, played in the church youth band and was known for his guitar solos.

"Nehemiah is a loving kid. He loved his family and he made a really terrible mistake and we don't know why he did it," said his older sister, Annette Griego. "We don't know whether he had a mental breakdown. We just don't know. We don't have answers."

Nehemiah Griego has been in custody since Jan. 19, when authorities say he shot his parents and siblings in their home in a rural area south of Albuquerque.

His parents, Greg and Sarah Griego, were well-known throughout the community for more than a decade of ministry work with inmates at the county jail. Greg Griego, an Army veteran, also served as a pastor at one of Albuquerque's largest Christian churches and was a volunteer chaplain with the local fire department.

Bernalillo County Sheriff Dan Houston has said the teen told detectives he was angry with his mother and had been having homicidal and suicidal thoughts.

Family members have been critical of how the investigation has been handled and are pushing for a psychiatric evaluation for the teen in hopes of finding out what led to the violence.

Griego has been classified as a serious youthful offender and is facing charges as an adult. His relatives said they forgive him and prefer that he be tried as a juvenile.

"For us, justice is what the victims of this crime would want and what they would have wanted is for us to do everything we can to make sure that Nehemiah is given the fairest chance to turn his life around, that he not be cast away to an adult prison system where he can never have an opportunity for redemption," said Eric Griego, the boy's uncle.