Police in the small town of Grantsville released the names of the victims, who ranged from 14 to 52 years old, and said the boy was related to them. But authorities declined to specify the suspect's age, his relation to the victims or release his name at the request of the district attorney until formal charges are filed.
The father of the family was released from the hospital after being treated for a gunshot wound and was talking with investigators, said Police Sgt. Rhonda Fields. She added that the killings were the first homicides in two decades in the town of 11,000 about 35 miles (55 kilometers) west of Salt Lake City.
“The biggest question everybody has is 'why' and, while we may not be directly able to answer that, we hope to be able to gather some information to be able to help people in future to be able to prevent something like this or offer support to those who may need it," Fields said.
“We don't have a lot of crime," she added. “It's hard to accept that something like this has happened in our community Investigators were trying to put together a timeline of the shooting to help figure out what happened, Fields said, adding that no other details were being released at this time.
Hundreds of people gathered Monday night for a candlelight vigil for the family where some expressed compassion for the boy arrested. “On so many levels this is so tragic for our community," family friend Diane Passey said, according to the Deseret News. “Not just for the mother and the four lives lost, but also for the poor young man who was in such a dark place.”
Relatives of the victims asked for privacy as they awaited results of the investigation. Patty Deakin-Daley, a realtor who started a fundraising campaign to help cover the victims' funeral expenses, said she had been in touch with a brother and a son of the injured father, Colin Haynie, 50.
A statement from the Haynie family that Deakin-Daley read at the vigil expressed both their deep sorrow and their appreciation of the outpouring of love. “It is our hope and prayer that at this difficult time we focus on the positive moments that we have shared together. We are finding for ourselves that as we mourn, it is beneficial - if not necessary - to cheer our spirits with good memories, and even a bit of laughter," it said.
Police responded to a call of shots fired inside the family's home at approximately 7 p.m. Friday. When officers arrived, they found the bodies of Consuelo Alejandra Haynie, 52, her daughters Alexis, 15, and Maylan, 14, and son Mathew, 14, Fields said.
The shooter and his father were gone, she said. Authorities later discovered that a person who arrived at the house after the shooting drove the suspect and the surviving victim to a nearby hospital, Fields said.
Authorities said they had not been called to the house in the past. Officers arrested the boy at the hospital. He faces four counts of aggravated murder, one count of attempted aggravated murder and multiple firearms charges and was being held at a youth detention facility pending an expected court appearance.
Officials said he is the only suspect. The person who drove them to the hospital was not involved in shooting, she said. It appears to be the largest mass shooting in Utah since 2007, when a shotgun-wielding gunman killed five people and himself at Trolley Square mall in Salt Lake City.
Tooele County School District officials will offer counseling to students this week. Counselors will also be at the city library for anyone else in the community who needs to talk about the killings, Grantsville Mayor Brent Marshall said.