Detectives say the suspect was shot twice and was lying just outside the doors when officers arrived around 12:15 p.m. Sunday.
The suspect died at a hospital.
Metro Police Lt. Les Lane tells the Las Vegas-Journal the sword was at least three-feet long.
Authorities say the shooting appears to have been in self-defense but that detectives were investigating whether the gun used was properly registered.
They say only two employees and no customers were present at the time of the shooting.