The Perfect Weapon

The Perfect Weapon is a 1991 actionmartial arts film starring acting newcomer Jeff Speakman.

Jeff Sanders Jeff Speakman leads a double life by day, he is a simple, unassuming construction worker, and by night, an expert Kenpo student and master of his craft.When Jeff lost his mother as a teenager, he became an outcast and frequently lashed out at his family and society in an attempt to assuage his anger. His father, Captain Sanders Beau Starr, gained the idea from a mutual friend, Kim Mako, to enroll Jeff in a Kenp school to better manage his rage and feelings. But one day, he got into a fight with a bully who beat up his younger brother, and severely injured him with his martial arts. Displeased with his lack of selfcontrol, Jeffs father forced him to move out of home. Jeff, now estranged from his family and living alone, continued with his courses in Kenpo and eventually gained Kim as a mentor and father figure. ........

Source: Wikipedia