ALBUQUERQUE, N.M. (AP) - The New Mexico teenager accused of fatally shooting his parents and three younger siblings told authorities he was annoyed with his mother and had been having homicidal and suicidal thoughts, according to a probable cause statement. Nehemiah Griego, 15, remained in custody Monday on charges of murder and child abuse resulting in death. He was arrested following the shootings Saturday at a home in a rural area southwest of Albuquerque where he lived with his family. A Bernalillo County sheriff's detective questioned the teen Saturday night and the details of their conversation were spelled out in the statement. The teen allegedly told the detective that he took a .22 caliber rifle from his parents' closet around midnight Saturday and shot his mother in the head while his younger brother slept next to her. Griego told the detective that his brother did not believe him that their mother was dead so he showed his mother's bloody face to his brother and then shot him, according to the statement. He's accused of then shooting his two young sisters in their room. He retrieved an AR-15 rifle from his parents' closet and waited in a downstairs bathroom for his father to come home. The statement said he shot his father multiple times after he passed the bathroom doorway. The teen said he reloaded the guns so "he could drive to a populated area to murder more people," according to the statement. His plan, the statement said, was to "shoot people at random and eventually be killed while exchanging gunfire with law enforcement." Sheriff's spokesman Deputy Aaron Williamson said Monday he couldn't immediately comment on the document. Detectives have spent two days collecting evidence and trying to piece together what led to the violence. "There's no other way to say it, except that we have a horrific crime scene down there that we are working on," Bernalillo County Sheriff Dan Houston said Sunday. The detectives had finished their work at the home by Monday afternoon. The metal gate at the home's entrance was shut, a small bouquet of purple flowers was on the top of the gate and at each side there were religious signs, including one that read "Jesus is the reason for the season." The sheriff's office identified the victims as Greg Griego, 51, his wife Sarah Griego, 40, and three of their children: a 9-year-old boy, Zephania Griego, and daughters Jael Griego, 5, and Angelina Griego, 2. All appeared to have gunshot wounds to the head. Greg Griego was a pastor who had once served at Calvary, one of Albuquerque's largest Christian churches. He was also well-known throughout the law enforcement community for his work as a voluntary chaplain. Neighbor Terry Wootan described Griego as a man with a big heart. The two sometimes chatted at the mailbox and would wave to each other when passing by. Wootan said Griego told him about his time in California when he was involved in gangs and how he turned his life around and found God. "What he wanted to do was help people, and he would never quit," Wootan said. The pastor's death has shocked the community, including the Albuquerque Fire Department and the Metropolitan Detention Center, where he volunteered his spiritual guidance. A records check by the Children, Youth and Families Department indicated no trouble with the Griego family and that Nehemiah Griego had never been in trouble with the law. "This youth had no history with the juvenile justice system," agency spokesman Bob Tafoya said Monday. Williamson confirmed there was no history of any emergency calls to the home in the recent past. According to the probable cause statement, Nehemiah Griego first told a staff member at Calvary that his family was dead and that he placed the two rifles in the family van as protection before driving to the church. He later changed his story, according to the detective's statement. Asked if he had told anyone else about murdering his family, Griego allegedly told the detective that he had taken a picture of his dead mother and sent it to his girlfriend. Sheriff Dan Houston plans to hold a news conference Tuesday morning, and the teen could make his first court appearance in the next day or two. Associated Press writer Paul Davenport in Phoenix contributed to this report.