Butterfield, a 43-year-old Army veteran, was airlifted to the hospital after a passing motorist saw him lying on the ground and called 911. Butterfield died during emergency surgery.
“Tonight we lost a hero,” Michigan State Police director Col. Kriste Kibbey Etue said in a statement. “The entire MSP family, as well as our greater law enforcement family, mourns alongside the Butterfields. Trooper Butterfield’s sacrifice will never be forgotten; may he rest in peace.”
Though it's unclear why Butterfield pulled the car over, police identified two suspects based on information he gave to dispatch before the shooting. A few hours later, they exchanged gunfire with the suspects at a Manistee County gas station. The male suspect was shot and taken to a nearby hospital. A female suspect is also in custody.
Michigan State Police Lt. Chris McIntire said authorities had yet to identify a motive.
“We don’t know yet,” he said. "We spent a lot of time last night… talking to both suspects. There’s not a lot I can say about the investigation. We have a lot of work to do yet, and we’re trying to piece it together."
Michigan Gov. Rick Snyder said that Butterfield's death served as a "grim reminder" to all Michiganders.
“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,” Snyder said in a statement.
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.
Notable deaths of 2014 [PHOTOS]