Terry J Sedlacek, 27, of Troy, was charged with two counts each of first-degree murder and aggravated battery, said Stephanee Smith, spokeswoman for Madison County Prosecutors.
The gunman strode down the aisle of the First Baptist Church shortly after 8am and briefly spoke with The Rev Fred Winters, then pulled out a .45-caliber semiautomatic pistol and began firing until it jammed, Illinois state police director Larry Trent said.
Churchgoers wrestled the gunman to the ground as he waved a knife, slashing himself and two other people, Trent said.
None of the 150 congregants seemed to recognise the gunman and investigators do not know details of Winters’ conversation with him, but they planned to review an audio recording of the service, Trent said. The service was not videotaped.
“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 realising that he had wounded the pastor.”