LUDINGTON, Mich. -

Authorities say a Michigan state trooper played a key role in leading police to the person they believe fatally shot him during a traffic stop.

State police Lt. Chris McIntire said Tuesday Trooper Paul Butterfield provided location and vehicle information to a dispatcher before he was shot Monday evening in Mason County.

Three minutes later a motorist called 911 saying a trooper had been shot in the head. The 43-year-old Butterfield died during surgery.

Butterfield worked from the Hart Post. He joined the state police in 1999 after serving in the U.S. Army.

Sherman Township is 80 miles north of Grand Rapids.

Police located two suspects at a store around 8:30 p.m. Police and the suspects exchanged gunfire and one suspect was shot.

The man and woman were taken into custody.

Gov. Rick Snyder says Butterfield's death is a "grim reminder" of the dangers involved in protecting the public.

He ordered U.S. flags on all state buildings be lowered to half-staff in honor of state Trooper Butterfield. Snyder announced the lowering Tuesday and says the flags will remain at half-staff until after Butterfield's funeral.

Statement from Gov. Rick Snyder on Butterfield's death:

“This senseless incident is a grim reminder that our brave public safety officers put their lives on the line every day when they go to work protecting Michiganders. They are heroes.

Our hearts break when a Michigan State Police trooper, or any of our other police officers or firefighters, is killed in the line of duty. Their loss is unquestionably felt by their families as well as the communities they serve and our entire state. We realize the extraordinary difficulty of their jobs and the sacrifices they make for us.

A tragic event like this shakes us all, but it also bolsters our resolve to make our streets and our neighborhoods safer.

We thank Trooper Butterfield for his bravery, his service and his sacrifice. Our thoughts and prayers are with him, his family, friends, and colleagues.”