Rapper Tupac Shakur is in critical condition at University Medical Center in Las Vegas. Shakur and Death Row Records Chairman Marion Knight were shot several times on the Vegas strip after attending the Tyson-Seldon heavyweight boxing title fight. Shakur underwent surgery for gunshot wounds to the chest Sunday. The 25-year-old is expected to live. Knight received a minor gunshot wound to the head. Police are questioning witnesses but have not made an arrest.The rapper was shot five times in a No