Three troopers were wounded in a shootout with Jeff Michaels, the Pittsburgh Post-Gazette reported.
The first victim was Kimberly Scott, 58, who was shot at the Juniata Valley Gospel Church in Frankstown, near Hollidaysburg.
Beverly McCaulley, a former pastor's daughter-in-law, told the Post-Gazette Scott was helping decorate the church for a children's Christmas party.
Michaels lived about half a mile from the church on Juniata Valley Road. Two men were shot outside another home on the same road.
Several miles of the road became a crime scene and were closed.
Neighbors said the other victims were Kenneth Lynn and William Rhodes, his son-in-law.
Marla Finn, a spokeswoman for the state police, said one trooper was injured in a head-on collision with Michaels' pickup truck, The Altoona Gazette reported. A second trooper was hit by gunfire that struck his body armor and a third by broken glass when bullets broke the windows of a police car.