Three Wisconsin men are charged after a homemade 'cannon' exploded and killed their friend at a reunion party.
The trio are charged in Marion, Waupaca County with homicide by negligent handling of explosives, a felony.
On June 11, 42-year-old Kenneth Niemer waived a preliminary hearing and entered a not guilty plea, WLUK reported.
The trial date has not yet been scheduled, court records show.
Kenneth Niemer, 42, of Clintonville, (pictured) has entered a not guilty plea over the May 26 death of his friend Paul Casperson
The other two men, father and son Scott Mattes, 60, and Robert Mattes, 37, have not yet entered their pleas.
WLUK-TV reports that they were using a four-foot-long, half-inch-thick steel pipe with a plug welded onto the bottom at Scott Mattes' home in Marion.
According to the complaint, after the first attempt to ignite the device failed, it exploded during the second try, sending a piece of shrapnel that killed 44-year-old Paul Casperson of Illinois on the evening of May 26.
Casperson died of a 'penetrating fragment wound of abdomen' and the steel piece of shrapnel was removed during the autopsy, the complaint says.
All three suspects appeared in court on the afternoon of Wednesday May 29, after which all three were released on $25,000 signature bonds.
