MANISTEE, Mich. (WZZM) -- There will be two trials for a man charged with the murder of a Michigan State Police trooper.
The first, January 15 in Manistee County where a jury will decide if Eric Knysz stole a car and illegally possessed a gun. Then February 18, a trial in Mason County to decide if Knysz killed Michigan State trooper Paul Butterfield.
WZZM 13's Jon Mills Eric Knysz' father, Jack, who says if his son is guilty of murder, drug use is to blame.
Tuesday Jack Knysz sat quietly behind his daughter-in-law as she found out she would face car theft charges in Manistee County. Outside the courtroom, the former police officer spoke about the death of Trooper Paul Butterfield.
"I know how law enforcement feels about that and we are sick about that," Jack Knysz told WZZM 13.
His son Eric is accused of firing the single shot that killed Butterfield during a traffic stop September 9.
"That wasn't my son that did this OK? It was the drugs."
Drugs Jack says Eric was using to deal with a painful shoulder injury. Eric was making a living climbing, cutting, and harvesting trees. The shoulder pain Jack believes sent his son down a path leading to unknown illegal drugs.
"He went to the hospital, took more drugs and that did not help. So he bought some on the street and apparently whatever he took, it was more than enough to make him lose control."
September 8 Jack says he noticed something out of place with Eric. Possibly signs of the strengthening grip illegal drugs and prescribed drugs were having on his son.
Now Jack wonders about the condition of Eric's mind the night the trooper died. "For all we know, the drugs could have made him think the trooper was the devil."
Drug use will likely be a part of Eric's two scheduled trials, with juries being asked weather or not drugs are to blame for Eric's alleged actions.
"My son was 19 years old, he did get in trouble and do minor things, but the drugs are what set him off," said Jack Knysz.
RELATED: Sarah Knysz to stand trial in death of Butterfield
Eric's wife Sara is also charged in both Manistee and Mason counties. Her trials on auto theft and accessory after the fact to murder will be held separate from her husband.