Updated

A man who witnesses said went on a tirade after rescheduling a mental health clinic appointment was shot dead by the owner of a neighboring business in Houston.

The shooting happened Wednesday inside a building where the Texas Department of Assistive and Rehabilitative Services is housed in southwest Houston.

Police Detective Willis Huff says the man appeared at the clinic for an appointment when the staff rescheduled him because he said he wasn't feeling well. The man left, but witnesses said he returned within a half-hour and was yelling and kicking at glass doors.

Huff said the man continued his tirade at a neighboring business, where the owner had a gun and shot him dead.

Police say the shooter was licensed to carry a gun and is being interviewed.