Montgomery County District Attorney Risa Vetri Ferman has confirmed the deceased as the 17-year-old son of Hatfield Township Police Lieutenant Eric Schmitz.
Friends tell Action News the teen's first name is Stephen.
It all happened at a home on the 100 block of Oxford Road in Towamencin Township around 2:30 p.m. Wednesday.
According to police, Lt. Schmitz fatally shot his son after the teenager attacked him with a large, fixed blade hunting knife inside their home.
Authorities say the knife has a five inch blade and has an overall length of ten inches.
A source tell Action News the shooting appears to have been in self defense.
Police say Lt. Schmitz has been cooperative with detectives and is being interviewed at a local hospital where he is receiving treatment for his injuries.
Towamencin Township police have received calls from the home twice in the recent past.
On April 30, police were called because the 17-year-old was reportedly enraged. There were reports that he had made vague threats to harm himself in the past. According to officials, the tensions caused by Stephen subsided and Lt. Schmitz indicated to police that he did not believe any further action was necessary.
On May 26, police were called and responded to the home based upon a report that Stephen was threatening to kill himself. Lt. Schmitz prevented his son from harming himself on this occasion, and the teen was involuntarily committed that same day to the Horsham Clinic. The teen remained committed at the Horsham Clinic for thirteen days. He was released on June 7.
A Facebook memorial has been set up with dozens of statements posted; one reads, "Nothing explains why this had to happen to you I love you Stephen. Rest easy.
Detectives are currently processing the scene, conducting interviews, and investigating the background and relationships of the family members and the deceased.
Police are asking anyone with information about the recent behavior of Stephen, including threats made towards family members or others, to contact the Montgomery County Detective Bureau or the Towamencin Township Police Department.