The shooting happened around 5:00 p.m. on Tuesday on the 13,000 block of Mar Penn Avenue.
Police say John Fleagle shot and killed his wife, Cathy, with a handgun at their home in Rouzerville.
He then shot his wife's son, Mitchell Robinson, 18, in the arm and then shot and killed himself.
Pennsylvania State Police were contacted to handle the investigation because John Fleagle was a former police officer for the Washington Township Police Department.
Cathy Fleagle had been working as an administrator for the department.
The motive for the shootings is unknown.