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PHOTO: BCSO Deputies and crime scene personnel work the scene of a five person homicide in Albuquerque, NM, Sunday Jan. 20, 2013.

New Mexico officials are trying to determine why a teenager opened fire with an assault rifle on his family this weekend, killing his parents and three young siblings.

Nehemiah Griego, 15, used the assault rifle to kill his father, Greg Griego, 51, a pastor at Calvary Church in Albuquerque, and mother, Sara Griego, age 40, as well as the three younger siblings, ages 9, 5, and 2, said officials in Bernalillo County, N.M.

Police said that multiple firearms were found at Griego's home after the attack, including an assault rifle.

Nehemiah Griego has been arrested and charged with two counts of murder, and three counts of child abuse resulting in death, according to the Bernalillo's Sheriff's Department.

Sheriff's deputies said they received an emergency call around 9:15 p.m. Saturday, and arrived to find all of victims with gunshot wounds, according to ABC News affiliate KOAT.

"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 told KOAT.

Officials from Calvary Church, where Greg Griego acted as pastor, said that the family were deeply involved in the church and loved by the community, according to the report.

Greg Griego's brother, Eric, a former city councilor in Albuquerque and state legislator, released a statement Saturday about the murder.

"Our family is grieving this terrible tragedy. We appreciate the prayers and support we have received and request that the media honor our family's privacy during this difficult time," the statement read.

The sheriff's office declined to given any other details on the murder today, citing the investigation. They will hold a press conference Tuesday, where they are expected to release more information.

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