The Night Stalker 1972
Wisecracking reporter Carl Kolchak investigates a string of gruesome murders in Las Vegas. It seems that each victim has been bitten in the neck and drained of all their blood. Kolchak is sure that it is a vampire. He's hot on the trail, but nobody believes him. His editor thinks he's nuts and the police think he's a hindrance in the investigation, so Kolchak takes matters into his own hand.