The Insatiable (2006)
A drab, run-of-the-mill guy witnesses a vampiress devour a bum and becomes so infatuated with her, he tracks her down and traps her in a basement so she can't kill again.
A drab, run-of-the-mill guy witnesses a vampiress devour a bum and becomes so infatuated with her, he tracks her down and traps her in a basement so she can't kill again.