The suspect was striking the victim in the head and neck as he pinned him down by sitting on his chest.
Investigators said the suspect repeatedly ignored orders to drop the meat clever and was fatally shot by a deputy. The suspect suffered three bullet wounds and died at the scene.
The woman's boyfriend is expected to survive.
A motive for the attack is unclear.
The identities of those involved in this incident were not immediately released.
City News Service contributed to this report.