MISSOULA, Mont. (AP) — A Montana man has pleaded not guilty to a new homicide charge in a fatal shooting where two people died and two people were wounded, including a Montana Highway Patrol trooper.

Johnathan Albert Bertsch, 28, now faces two counts of deliberate homicide in the deaths of Julie Blanchard and Shelley Hays and two counts of attempted deliberate homicide in the March shooting, Missoulian reported Thursday.

Bertsch was originally charged with one count of deliberate homicide in the death of 28-year-old Hays before being charged with another count when 52-year-old Blanchard later died in June from gunshot wounds sustained during the shooting, prosecutors said.

Bertsch allegedly shot up a vehicle carrying three people and later ambushed a state trooper searching for him shortly after midnight, authorities said.

Investigators reviewed security footage from a tavern on the night of the shooting, authorities said. Julie Blanchard had arrived to pick up her son and his friend Hays while Bertsch was there to speak with his father, court records said. Both were leaving at about the same time, records said.

“Before leaving the parking lot, the red pickup driven by Julie briefly stopped and emitted an extremely large and dense cloud of diesel exhaust,” prosecutors said. “After the cloud of diesel exhaust enveloped the vehicle driven by Jonathan, he abruptly pulled out and followed the pickup.”

Blanchard told officers that a white SUV had followed her pickup, began flashing its lights and then shots were fired, authorities said. Hays died at the scene and Blanchard died weeks later.

The deaths were ruled homicides, coroners said.

Montana Highway Patrol Trooper Wade Palmer was shot in the head, face and neck early the next day near Evaro after reporting he had spotted the suspect’s vehicle, authorities said.

Palmer is now recovering at home after treatment at University of Utah Hospital in Salt Lake City, authorities said.

Bertsch is scheduled for trial in August.