The teen suspected of gunning down his parents and three siblings in their New Mexico home told police he reloaded his assault rifle and was planning to go to a “populated area to murder more people,” police said.

Nehemiah Griego, 15, who local residents described as a loner who always wore camouflage military fatigues, told police he had been plagued by “suicidal and homicidal thoughts,” according to a sworn affidavit provided to prosecutors by the arresting officer and obtained by

“Nehemiah said after killing five of his family members, he reloaded the weapons so that he could drive to a populated area to murder more people,” the report states. “Nehemiah stated he wanted to shoot people at random and eventually be killed while exchanging gunfire with law enforcement.”

Griego has been charged with five counts of murder and three counts of child abuse resulting in death. Prosecutors have yet to decide whether to charge him as an adult.

Police say he killed his parents, Greg and Sara Griego, and three of their children with an assault rifle. The report says Griego, who waived having an attorney present, described how he first killed his mother, then the siblings, ages 2, 5 and 9, before lying in wait for his father in the wee hours.

At some point, he said he took a picture of his dead mother and emailed it to his girlfriend, who either called 911 or told a family member who did. When police arrived, they found an AR-15 assault rifle and a .22 caliber rifle with a scope in a vehicle at the home. The youth told police the guns came from his parents' closet.

The youth, who is listed in the police report as just 5-foot-8 and 105 pounds, initially told police he came home early Saturday after being at a friend’s house for several days and found his family dead in the locked home. But police say his story quickly unraveled and he confessed.

Police still could not say what sparked the violent rampage. Local residents said the teen was almost always seen by himself and wore military-style clothing. Griego was not registered as a student with the Albuquerque Public School District, but police could not confirm if he had dropped out or was being home-schooled.

Griego appears in an online dating site called wearing military fatigues with the comment: "I'm a fun-loving guy who [likes] to make [people] happy; I might be shy but I'll open up once you get to know me." The site does not correctly list his age.

A spokesman for the New Mexico child welfare agency said the agency had had no contacts with the boy or his family. The Associated Press reported finding no records indicating the teen had ever been involved with the juvenile justice system, and investigators say there was no history of any emergency calls to the home in the recent past.

Greg Griego, who was 51, was a pastor of a local church before taking a leave of absence and had volunteered as chaplain for the Metropolitan Detention Center. Sara Griego was 40, and the children, Zephania, Jael and Angelina, were 9, 5 and 2, respectively.

"All of the victims appeared to have been shot multiple times," Aaron Williamson, spokesman for the Bernalillo County Sheriff's Department, told

District Attorney Kari Brandeburg's office will weigh whether to prosecute the 15-year-old Griego as an adult or minor. He was set to be arraigned on Tuesday.