The incident occurred at a church on East Swamp Road in Milford Township, Bucks County, on Sunday, Dec. 15 at approximately 9 a.m., state police said.
The man attended the service and returned home, leaving his firearm behind under his seat in the nave, according to authorities.
A church member discovered the weapon while cleaning and contacted state police.
The owner of the firearm was identified, and charges are pending approval from the Bucks County District Attorney's Office, troopers said.
Click here to follow Daily Voice West Grove-Avondale and receive free news updates.