The Night Strangler(1973)

After being run out of Las Vegas, reporter Carl Kolchak heads for Seattle and another reporting job with the local paper. It's not long before he is on the trail of another string of bizarre murders. It seems that every 21 years, for the past century, a killer kills a certain number of people, drains them of their blood and then disappears into the night. Kolchak is on his trail, but can he stop him?