(CNN) -- Matthew Murray, the man who police say shot and killed four people at two separate locations in Colorado on Sunday, died from a self-inflicted gunshot wound, the coroner's office said Tuesday.
A former roommate took this photo of Matthew Murray performing in a 2002 Christmas program.
"The death of Matthew Murray has been ruled a suicide," the El Paso County Coroner's Office said in a statement.
"It should be noted that he was struck multiple times by the security officer, which put him down. He then fired a single round killing himself," the statement said.
Police Sgt. Skip Arms told The Associated Press that Murray shot himself in the head.
Police say before Murray, 24, went down, he shot and killed sisters Stephanie and Rachael Works, ages 18 and 16, and wounded their father, who was in or near their car in the parking lot of New Life Church in Colorado Srings, Colorado.
Murray also wounded two other people with his assault rifle as he re-entered the church.
One of them, Larry Bourbonnais, described the gunman to CNN. "He was all in black. And he was very calm and collected, just, not moving his head from side to side, but he was just kind of checking things out," Bourbonnais said.
Bourbonnais said he tried to distract the shooter before security guard Jeanne Assam made her move. Watch Bourbonnais describe the scene at New Life »
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Assam said she found cover in the lobby after Murray opened fire in the church parking lot and walked into the building. She said she waited for him to approach, identified herself as a security guard, and shot him -- "and that's pretty much it."
"I'm telling you right now, she's the hero, not me. It was the bravest thing I have ever seen," Bourbonnais said. "She had no cover. He fired -- I heard him fire three. I heard her fire three. And she just began -- she kept yelling 'Surrender!' the whole time. And she just walked forward, like she's walking to her car in the parking lot, firing the whole time."
Bourbonnais said when he and Assam reached Murray, "he had slumped backwards, slid down on the floor, and expired."
The assault at New Life Church came about 12 hours after Murray shot and killed two people and wounded two others at the Youth With a Mission center in Arvada, Colorado, 80 miles away, police said.
Brady Boyd, senior pastor of New Life Church, told reporters Tuesday he and his church had already forgiven Murray, even though he is still angry about what happened.
"But being angry and being unforgiving are two different things," Boyd said.
"I forgave him immediately. I can't imagine what caused him to do that. I'm sad for his parents, who are having to bury a young son. But forgiving him was an immediate response of our heart," the pastor said.
He also vowed that his congregation would hold its regular services as scheduled next weekend.
Boyd said members will hold a family meeting Wednesday. "We will gather to worship, pray, mourn and begin our healing process," a statement said.
That process would be helped if the reason Murray committed these acts was known, the pastor said.
"If we could find some motive, some written motive or some recorded motive that he gave, it would be helpful for the healing process, sure, because that is the question: Why? Why, why, why is going to be the number one question that we answer," he said.
Some answers may be gleaned from a warning Murray posted online just 90 minutes before he went to New Life Church.
The message attributed to Matthew Murray -- using the screen name "nghtmrchld26" -- mirrored the wording of a warning posted by in 1999 by Eric Harris before he and Dylan Klebold went on a shooting rampage at Columbine High School.
"I'm coming for EVERYONE soon and I WILL be armed to the @.%$ teeth and I WILL shoot to kill," the posting obtained by KUSA read. This was the same wording used by Harris, with the exception of symbols used to replace an expletive.
Murray, who lived in Englewood, Colorado, just 13 miles from the Columbine campus, titled his entry "You Christians brought this on yourselves." It was published on a Web site for people who had left Pentecostal and fundamentalist religious groups.
The message, first reported Monday by CNN affiliate KUSA-TV, was taken off line by the site's administrator after he talked to the FBI.
The posting on the online forum -- maintained by the group Association of Former Pentecostals -- indicated it was published at 11:03 a.m. on Sunday. The New Life Church shooting happened at 1:10 p.m. on Sunday. The shooting at Youth With A Mission happened shortly after midnight, Saturday.
A memorial service was scheduled for Wednesday for the two staff members there who were killed, Tiffany Johnson, 26, and Philip Crouse, 24, according to the group's co-founder, Peter Warren.
Richard Werner, 34, told CNN Monday that he trained with Murray at the center in 2002. He said Murray exhibited strange behavior -- including saying he heard voices -- and was told that he would not be allowed to join the group on a mission trip to Bosnia.
The Youth With A Mission center said that "Murray was briefly a student at the YWAM Arvada training center in 2002. He was enrolled in a Discipleship Training School but did not complete the program."
Warren said Murray was not allowed to join the trip because of unspecified health concerns.
A branch office of Youth With A Mission was located at the New Life Church in Colorado Springs, sources said.
A YWAM statement said the Works sisters had participated in one of their programs. The girls were "involved with a summer outreach organized by New Life Church and a ministry of YWAM which rents office space in the New Life campus," the center said.
