From Meridith Edwards, Rick Martin and Melissa Gray
(CNN) -- Sheriff's investigators combed through what one called a "horrific" crime scene Sunday after the shooting deaths of five people, three of them children, at a home outside Albuquerque, New Mexico.
A well-known local pastor and four of his relatives were among the victims, according to those who knew him.
Each victim was shot multiple times, said Lt. Sid Covington of the Bernalillo County Sheriff's Department, and one of the weapons used was what he described as an assault rifle. Sheriff Dan Houston said a 15-year-old boy, who "may be a family member," was charged with two counts of murder and three counts of child abuse resulting in death.
"Initially responding deputies entered the home and found the five deceased inside the residence, so obviously it was a very gruesome scene," Covington told reporters. There was no indication of a motive so far, he said.
"It's a large crime scene with a lot of physical evidence, and because there's an offender in custody, we're doing our best to be thorough and complete in gathering any potential evidence, and so we're going slowly, methodically, through the entire residence," Covington told CNN.
Investigators said the dead included a man, a woman and three grade-school-age children -- two girls and a boy.
They did not release the names of the victims, saying the process of formally identifying the remains was still going on, but they said the home belongs to Greg and Sarah Griego. Greg Griego was the chaplain for the Albuquerque Fire Department and involved in several prison ministries.
"Chaplain Griego was a dedicated professional that passionately served his fellow man and the firefighters of this community," read a statement from Fire Chief James Breen. "His calming spirit and gentle nature will be greatly missed. Our thoughts and prayers go out to Greg's extended family."
Griego was also a former pastor at Calvary Church, where the family still attended services, church member Brian Nixon told CNN affiliate KOAT.
Griego's brother, former state Sen. Eric Griego, issued a statement saying, "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 family lived in a large home at the end of a street on the southwestern edge of Albuquerque. Neighbor Terry Wootan described it as a semi-rural area with farms and residences.
"It's a very quiet, decent neighborhood," Wootan told CNN. "Across America we hear it: 'Something like this could never happen in my neighborhood.' But I woke up at 5:30 this morning to floodlights and crime investigation vehicles, and it's just not something you think you're going to wake up to."
The sheriff said deputies were dispatched to the home around 9:15 p.m. Saturday. They were summoned by "a party that was called by the suspect," he said, but "I don't know what the dynamics of that relationship is."
He said investigators are unaware of any criminal history with the teen and were looking into whether any family members had a record. The boy is being charged as a juvenile, but prosecutors could charge him as an adult, Covington said.
CNN's Matt Smith contributed to this report.