Montgomery County detectives and Towamencin police say their preliminary investigation indicates that Hatfield Township Police Lieutenant Eric Schmitz shot and killed his 17-year-old son inside their Oxford Road home Wednesday afternoon. They also say the shooting happened after the boy attacked his father with a large hunting knife. This is not the first time Towamencin police have received calls about the teenager. Just over two weeks ago they were at the residence after the 17-year-old had threatened to kill himself. That incident resulted in the involuntary commitment of the boy at the Horsham clinic. He was released on Tuesday. Investigators say Lieutenant Schmitz is cooperating with them and recovering from injuries sustained during the attack of his son.