JUNEAU — A 19-year-old Beaver Dam man who is charged with using improvised explosive devices to blow up a portable toilet and mailbox now faces additional gun-related charges in a separate case.

Stephen D. Peterson is charged with first degree reckless endangerment and endangering safety by reckless use of a firearm for allegedly firing a gun into two  motor homes located in the towns of Lowell and Oak Grove on April 4, 2008.

The lead investigator in the case reportedly suspected Peterson of the shootings after learning that a Horicon police officer had found a .308 Winchester rifle in Peterson’s car during a routine traffic stop in June 2008.

According to the complaint, the detective followed up with Peterson, who denied firing the shots into the motor homes, and later told the officer he had given the gun to a friend.

However, a break in the case came in April 2009 when Peterson and two other men were arrested for suspicion of using improvised explosive devises to blow up a  portable toilet in Lost Lake Park on April 21, and a mailbox in the town of Burnett on April 20.

One of the suspects told police that Peterson had been responsible for shooting the homes in April 2008 with his Winchester .308 rifle.

According to the complaint, police used a search warrant to seize the gun and ballistics tests confirmed that Peterson’s rifle had been used to fire the spent shell casings found at the scene of both motor home shootings.

Peterson has been jailed on a parole hold since he was arrested in May on suspicion that he was responsible for the explosions.

Peterson faces a combined maximum 105-year prison term if convicted on three counts of being a party to possession of explosives for unlawful purposes and two counts of being a party to damage to property by use of explosives.

He is scheduled to return to Dodge County Circuit Court on those charges July 16.