ARVADA, Colo. – A gunman killed two staff members at a missionary training center early Sunday after being told he couldn’t spend the night, and about 12 hours later four people were shot at a busy megachurch in Colorado Springs.

Colorado Springs police Lt. Fletcher Howard said a suspect had been detained in the shootings at the New Life Church, but a source who was locked down at the church Sunday afternoon said a security guard had shot and killed the gunman. Authorities in Arvada, a Denver suburb about 65 miles north, said no one had been captured in the shootings there.

It was not immediately known whether the shootings were related, but Arvada authorities said they were sharing information with Colorado Springs investigators.

The mission training program has a small office at the church’s World Prayer Center on the New Life campus.

A gunman in a black trench coat and a high-powered rifle entered the church’s main foyer about 1 p.m. and began shooting, according to the source at the church, who spoke to The Associated Press on condition of anonymity because the police department had asked that it release all information.

The church’s 11 a.m. service had recently ended, and hundreds of people were milling about when the gunman opened fire. Nearby were parents picking up their children from the nursery.

The gunman was killed by a member of the church’s armed security staff, the source said. Four people were shot, and the source did not know whether the shooter was one of the four. A SWAT team was searching the building for an explosive device, but the source could not confirm any details.

Howard, who had characterized the shootings as occurring outside the church, declined to say whether the suspect had been shot.

The conditions of the four people shot at New Life were not immediately known, El Paso County Sheriff’s Lt. Lari Sevene said.

The first shooting happened at about 12:30 a.m. at the Youth With a Mission center in Arvada, a Denver suburb, police spokeswoman Susan Medina said.

A man and a woman were killed and two men were wounded, Medina said. All four were staff members with the center, said Paul Filidis, a Colorado Springs-based spokesman with Youth With a Mission.

Arvada Police Chief Don Wick said the suspect spent several minutes speaking with people inside the dorm. Peter Warren, director of Youth With a Mission Denver, said the man asked whether he could spend the night.

When told he couldn’t stay, the man opened fire, then left on foot, Warren said.

Warren said he didn’t know whether any of the students or staff knew the gunman. “We don’t know why” he came to the dormitory, Warren said.

Witnesses told police that the gunman was a 20-year-old white male, wearing a dark jacket and skull cap, who left on foot. He may have glasses or a beard.

Police with dogs searched the area through the night, and residents of nearby homes were notified by reverse 911 to be on the lookout. Medina said residents were asked to look out their windows for any tracks left in the snow during the night. About 4 inches of snow had fallen in the area in the past day.

Early Sunday afternoon, Lance Coles, a pastor at New Life Church in Colorado Springs, received a report that a man was shooting at people in the church parking lot and that the gunman may have entered the church, he told The Associated Press.

New Life was founded by the Rev. Ted Haggard, who was fired last year after a former male prostitute alleged he had a three-year cash-for-sex relationship with him. Haggard, then the president of the National Association of Evangelicals, admitted committing undisclosed “sexual immorality.”

The New Life church is one of Colorado’s largest with about 10,000 members.

Police in Arvada identified the victims of the shooting there as Tiffany Johnson, 26, and Philip Crouse, 23. Youth With a Mission said Johnson was from Minnesota and Crouse was from Alaska.

The missionary center identified the wounded as Dan Griebenow, 24, of South Dakota, and Charlie Branch, 22, whose hometown wasn’t immediately known. One of the men was in critical condition, and the other was stable, police said.

About 45 people were evacuated from the Youth with a Mission dormitory and moved to an undisclosed location.

The missionary center is on the grounds of the Faith Bible Chapel. Cheril Morrison, wife of chapel pastor George Morrison, said Crouse had just hung up Christmas lights at her home and that Johnson was “an amazingly beautiful person.”

Mimi Martin, who lives near the center, said she received the warning call at about 9 a.m. warning neighbors to keep their doors and windows locked.

“Why would anybody want to hurt those kids?” Martin said.

Darv Smith, director of a Youth With a Mission center in Boulder, said people ranging from their late teens to their 70s undergo a 12-week course that prepares them to be missionaries. He said the center trains about 300 people a year.

Filidis said staffers are usually former missionaries themselves and that the “mercy ministries” performed by trainees include orphanage work. He said he didn’t know where the group being trained in Arvada was going to be sent.

Youth With a Mission was started in 1960 and now has 1,100 locations with 16,000 full-time staff, Smith said. The Arvada center was founded in 1984.

AP Religion Writer Eric Gorski contributed to this report.