TUSCALOOSA, Ala. — The roommate of a man wounded in an Alabama shooting rampage said Wednesday that the violence started when the gunman came to their door looking for a black man, used a racial slur, and opened fire.

The witness also said the black man had been at the Tuscaloosa bar where later shootings wounded 17.

Authorities said they were not yet able to verify a racial motive.

Nathan Van Wilkins has been charged with 18 counts of attempted murder and will also face arson charges in the spree that included fires set at property owned by his former employer. It’s not clear what made him lash out, but he was recently fired from his job because of a fistfight and had filed for bankruptcy last year.

Brian Felton, 33, lives at the house where authorities say Wilkins wounded his first victim before going to the Copper Top bar near the University of Alabama campus. Felton said a man he lives with, who is white, answered the door late Monday, and the gunman asked for another roommate, who is black.

Felton said he heard the gunfire and found the white roommate bleeding. His roommate told him the gunman asked for the third roommate using the racial epithet.

A detective for the sheriff’s department said they had not been able to verify whether the target of the shootings had been at the house and the bar.

‘‘We haven’t had anything concrete that it was racial,’’ said Sergeant Kip Hart.

Felton is president of the Tuscaloosa chapter of the Legion of Doom Motorcycle Club. He and the roommate who was shot, Bruce Bankhead, own a tattoo parlor together and live in the home considered the group’s club house with their other roommate, Andrew Clements.

Neither Felton nor Bankhead know Wilkins, and they’re not aware that he’s affiliated with any motorcycle group, Felton said. Police said they had ruled out motorcycle gang violence as a reason for the shooting.