A woman fatally shot her ex-boyfriend in Pasco County Saturday night. And police are calling it a case of self-defense.

It happened just before 10:30pm in Zephyrills. Police say Frank Harrison, 45, went to his ex’s house armed with an assault rifle. Investigators say he had made threats against her before.

The ex-girlfriend says she opened the door and fatally shot Harrison.

At this point, no arrests have been made. Deputies believe it’s a case of self-defense.