TOWAMENCIN, Pa. (CBS) -- An argument between a father and son in Montgomery County ended tragically with a fatal shooting that left the son dead.

The shooting happened just after 2:30 p.m. on the 100 block of Oxford Road in Towamencin Township. Police say Hatfield Police Lieutenant Eric B. Schmitz was attacked by his 17-year-old son Stephen and shot him in self defense.

According to investigators, Stephen Schmitz attacked his father with a large, 10 inch, fixed blade hunting knife inside the family's home. Lt. Schmitz has been cooperating with the investigation and was interviewed at a local hospital where he is receiving treatment for his injuries.

The 17-year-old died at the scene of a gunshot wound to the chest.

Montgomery County District Attorney Risa Vetri Ferman and Towamencin Police say the Schmitz residence has been visited by police twice in the past for calls of disturbances. On April 30, police were called because the 17-year-old was 'enraged' and had made vague threats to harm himself. Then again on May 26, police were called when the boy threatened to kill himself.

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After the latest call, reports say, the son had been involuntarily committed to the Horsham Clinic where he remained for thirteen days before being released on June 7.

The incident remains under police investigating.