HARRISON COUNTY, Ind. (WXIN) — Investigators have revealed new details in the tragic death of a good Samaritan who stopped to assist a stranded driver along an Indiana road. He wound up dead after he was shot by the very person he was trying to help.

According to the Indiana State Police, Justin Moore, 31, of Owensboro, Kentucky, was traveling on State Road 135 just south of Palmyra when he ran out of gas. He pulled over close to 9:30 p.m. on Monday. Investigators learned that Moore had asked a local resident for gas—or gas money—before returning to his car, which was still partially in the road. Not long after, a reserve officer with the Palmyra Police Department arrived to assist Moore.

Investigators said Jacob Tyler McClanahan, 24, of Corydon, Indiana was traveling down State Road 135 in a pickup truck with a friend when he spotted Moore’s vehicle. McClanahan, a volunteer firefighter and employee of the county highway department, pulled over to offer his assistance to Moore and the police officer.

At some point during the officer’s interaction with Moore, investigators said the Kentucky man was asked if he had any weapons inside his vehicle. Moore told the officer he did not have any weapons in the car but was in possession of a small knife, according to investigators. The officer asked Moore to place the knife inside the vehicle.

Investigators said they aren’t sure what prompted Moore’s next actions. After he was asked to put the knife in his car, Moore allegedly opened his door, reached inside as if to put the knife away, but then quickly turned around with a shotgun in his hands and fired at the officer.

Investigators said the officer reacted, drawing his own sidearm and firing back at Moore. Moore fired the shotgun a second time, according to police, but it was McClanahan who was struck and killed by the shotgun blast. The reserve officer returned fire once more, investigators said, striking and killing the shotgun-wielding Kentucky man with his department-issued pistol.

State police said officers from multiple departments swarmed the scene in the wake of the frantic and sudden shooting. Life-saving measures were attempted on both Moore and McClanahan. The Palmyra officer was transported to the Harrison County Hospital after suffering a minor injury in the shootout.

Despite these new details, state police said investigators are still unsure why Moore was traveling in Indiana. No details have explained why he pulled out the shotgun to fire upon the very people who stopped to lend aid.

In the wake of the tragic shooting, the Harrison County Fire Department, where McClanahan was a volunteer, expressed shock over the seemingly senseless shooting. “Nothing makes sense that anyone could be murdered while stopping and rendering aid,” they wrote in a Facebook post. “Jacob is a true hero that will forever be remembered living the selfless life he did. A true firefighter that was always there when you needed help. Godspeed Jacob T. McClanahan. Your brothers at Harrison Township will miss you. Gone but never forgotten.”

McClanahan was an employee of the Harrison County Highway Department. They shared a post in tribute to their fallen coworker that included photographs. “Our hearts ache today over the senseless and tragic loss of our friend and coworker,” the highway department said in a Facebook post. “Jacob was very kind and had the true heart of a servant. Whether here at the Highway Department or with the fire department Jacob was always looking for ways to help people.”