The gunman strode down the aisle of the sprawling First Baptist Church shortly after 8 a.m. and briefly spoke with The Rev. Fred Winters before pulling out a .45-caliber semiautomatic pistol and shooting at the pastor, Illinois State Police Director Larry Trent said.
"We thought it was part of a drama skit ... when he shot, what you saw was confetti," said congregant Linda Cunningham, whose husband is a minister of adult education at the church. "We just sat there waiting for what comes next, not realizing that he had wounded the pastor."
The weapon jammed before the man could fire again, Trent said. The attacker then pulled out a four-inch knife, stabbing himself and two men who tackled him, he said.
Winters was pronounced dead at Anderson Hospital, hospital spokeswoman Natalie Head said.
Authorities didn't know whether Winters, a married father of two who had led the church for nearly 22 years, and the gunman knew each other. No one at the church seemed to recognize the 27-year-old gunman. Police would not release his name pending possible charges.
"We don't know the relationship (between the gunman and pastor), why he's here or what the circumstances came about that caused him in the first place to be here," said Illinois State Police Master Trooper Ralph Timmins.
The Rev. Mark Jones, another pastor at First Baptist, said he briefly saw the gunman but not the shooting, though he heard a sound like miniature firecrackers.
"We have no idea what this guy's motives were," Jones said outside the church.
Trent did not have details of Winters' conversation with the gunman.
"Right now all we know is that the suspect said something to the pastor and the pastor said something back," he said.
The gunman and one stabbing victim, 39-year-old Terry Bullard, underwent surgery at St. Louis University Hospital, spokeswoman Laura Keller said. Bullard was in serious condition, she said.
Keller did not release details of the gunman's condition or injuries.
The other victim, Keith Melton, was treated and released from Gateway Regional Medical Center, spokeswoman Kate Allaria said. A man who answered the phone at a listing for Keith Melton in Troy identified himself as Melton's stepson and said Melton had been stabbed but was going to be fine.
First Baptist had an average attendance of 32 people when Winters became senior pastor in 1987; it now has about 1,200 members, according to the church's Web site. Winters also was former president of the Illinois Baptist State Association and an adjunct professor for Midwestern Baptist Theological Seminary, according to the site.
"Our great God is not surprised by this, or anything," Nate Adams, executive director of the Illinois Baptist State Association, said in a statement. "That He allows evil and free will to have their way in tragedies like this is a mystery in many ways."
The red brick church sits along a busy two-lane highway on the east side of Maryville, a fast-growing village of more than 7,000 about 20 miles northeast of St. Louis. A farm sits directly across from the church, but subdivisions of newer homes can be seen from every side.
"Things like this just don't happen in Maryville," Mayor Larry Gulledge said. "We've lost one the pillars of our community, one of our leaders."
Sharla Dryden, 62, pulled into the church parking lot for a 9:30 a.m. service Sunday to see "just a lot of chaos, lot of police, fire, and people just devastated."
"They just said there had been a shooting," Dryden said. "I would have been devastated if anyone had been shot, but to hear it was the pastor was terrible. You just never expect this to happen at a church."
Last month, a man shot and killed himself in front of a cross inside televangelist Robert H. Schuller's Crystal Cathedral in Garden Grove, Calif. In November, a gunman killed his estranged wife in a New Jersey church vestibule as Sunday services let out.
Associated Press writers Betsy Taylor and Jim Salter contributed to this report.