BROOKFIELD, Wis. — A man police suspected of killing three people and wounding four by opening fire at a day spa was found dead Sunday afternoon after a six-hour search that locked down a shopping center, country club, and hospital in suburban Milwaukee.

Authorities said they believed the shooting was related to a domestic dispute. The man they identified as the suspect, Radcliffe Franklin Haughton, 45, of Brown Deer, had a restraining order against him.