A man in his 50s was stabbed in the head early Thursday morning in downtown Las Vegas. The suspect is his girlfriend’s father. The man said he and his girlfriend were walking near the Golden Nugget when the incident occurred, around 5 a.m. The man and his girlfriend contacted casino security and he was taken to a hospital with a laceration to his head. Police are not sure of a motive and are looking for the suspect, whose age is unknown.