Eric Knysz, the man found guilty in the murder of Trooper Paul Butterfield, was sentenced to life in prison Tuesday.
Knysz appeared in a nearly full Mason County courtroom to face his sentence. Several State Police troopers were in attendance.
Knysz was found guilty of murder of a police officer, felony firearms, carrying a concealed weapon, and unlawfully driving away as well as being a habitual offender in February.
At sentencing, the prosecution claimed Knysz has threatened to kill jail staff members. The defense claimed he didn't actually say that and the comment was taken out of context.
Prosecutor Paul Spaniola said Knysz's actions have not only impacted the local counties, but the state of Michigan as a whole.
Butterfield's fiancee, Jennifer Sielski, read a letter to the court.
"Today my wedding dress hangs in my closet next to Paul's MSP uniform," Sielski read. "Neither one ever to be worn again. Together they symbolize my dreams of living a life and having a future with my hero, my best friend, my life partner.
Dreams that were shattered by the actions of three irresponsible people September 9.
Butterfield's parents also spoke to the court.
"You certainly made a name for yourself with law enforcement," Paul Butterfield Sr. said. "But not the way our son did. I hope that everyday you think about what you've done in one selfish act of cowardice."
Knysz also briefly addressed the court for the first time after not taking the stand during the trial.
He apologized for the pain he caused Butterfield's family as well as his own family.
"I never meant for any of this to happen," said Knysz.
State Police Trooper Paul Butterfield was shot and killed in early September after making a traffic stop on the truck Knysz and his wife were driving in Mason County.
Knysz was arrested later that evening at a gas station in Manistee County.
In December, Kynsz's wife, Sarah, was sentenced to 2-5 years in prison for her part in the murder. She testified against her husband at trial.