Giant from the Unknown

The name of this movie is Giant from the Unknown released in 1958-03-01 and it's main theme is A series of grisly murders plague a small mountain community and the sheriff suspects a local scientist whom he dislikes. Together with a former professor and the professor's pretty daughter, the scientist sets about solving the crimes and discovers the killer is an oversized 16th century conquistador, resurrected by a lightning bolt from his mountain grave..