Police in Colorado say the man who killed four people at a church and missionary training center died of a self-inflicted shotgun wound.
Investigators had earlier suggested his death could have been a suicide, but they also credited a security guard with averting a greater tragedy by shooting the gunman after he entered the Colorado Springs church.
A county coroner's office concluded after an autopsy that Matthew Murray, 24, was shot multiple times by the security officer at New Life Church on Sunday but died after firing a single shot at himself.
Murray killed two people at the Youth With a Mission center in Arvada just after midnight on Sunday, police said. Murray had been dismissed from the center's missionary training program several years ago because of health issues, the center said.
Hours later, Murray killed two sisters in the parking lot at the New Life Church, according to investigators. Youth With a Mission had a program at the church, officials said.
Out for Revenge
In the hours between the killings, authorities believe Murray posted an anti-Christian diatribe on a Web site for people who have left evangelical religious groups.
"You Christians brought this on yourselves," Murray wrote, according to KUSA-TV in Denver. "All I want to do is kill and injure as many of you ... as I can especially Christians who are to blame for most of the problems in the world."
In the weeks leading up to the shootings, Murray had also posted other anti-Christian messages on the unidentified Web site, media reports said.
In an earlier post, Murray appeared to reject offers of psychological help. "I've already been working with counselors. I have a point to make with all this talk about psychologists and counselors 'helping people with their pain,'" he wrote, according to KUSA.
The station said Murray's posts were removed from the site after Sunday's killings, and that authorities were aware of them and are investigating. Police in Colorado Springs and Arvada would not comment on the writings.
Police said Murray had sent hate mail to the Youth With a Mission center in Arvada in the last few weeks after being removed from the program years ago.
The training center said health problems kept Murray from finishing the program. Murray did not complete the lecture phase or a field assignment as part of a 12-week program, the center said.
"The program directors felt that issues with his health made it inappropriate for him to" finish, it said.
'Greater Tragedy Averted'
Police and church leaders credited church member Jeanne Assam, a volunteer security guard who shot Murray, with averting a greater tragedy.
Assam, 42, said her faith allowed her to remain steady under pressure.
"It seemed like it was me, the gunman and God," she said, her hands trembling as she recounted the shooting during a news conference.
Assam is a former police officer who worked in Minneapolis during the 1990s, Minneapolis police Sgt. Jesse Garcia said. Garcia said Monday night that he didn't know the exact dates of her employment with the force and couldn't comment on why she left.
Family Stunned by Violence
Also Monday, officials finished searching the home where Murray lived along with his father and 21-year-old brother, Christopher. Murray's father, Ronald S. Murray, is chief executive of the Rocky Mountain Multiple Sclerosis Center in Englewood.
In a search warrant affidavit, investigators said Murray attended a home-based computer school and worked at his computer for three to five hours a day for the past two years.
A neighbor, Cody Askeland, 19, said the brothers were home-schooled, describing the whole family as "very, very religious."
Christopher Murray studied for a semester at Colorado Christian University before transferring to Oral Roberts, said Ronald Rex, dean of admissions and marketing at Colorado Christian.
Matthew Murray had been in contact with school officials this summer about attending the school but decided it was too expensive.
Police said Murray's only previous brush with the law was a traffic ticket earlier this year.
His relatives said they are grief-stricken and baffled.
"We cannot understand why this has happened. We ask for prayers for the victims and their families during this time of grief," said Phil Abeyta, Murray's uncle, who read a statement from the family.
From NPR reports and The Associated Press