Authorities say 37-year-old Thomas Hripto died from a self-inflicted gunshot wound.
Lower Pottsgrove Police Chief Mike Foltz says Hripto had not responded to the National Guard since last Friday, prompting a well-being check Wednesday.
Authorities say they heard a gunshot while responding and weren't sure if he was firing at them, so they called for assistance.
After more than five hours, officers entered the home and found Hripto dead in a second-floor bedroom.
Pennsylvania National Guard officials say Hripto was a member of the 2nd Infantry Brigade of the 28th Infantry.
