Marcelo Costa de Andrade — The Vampire of Niterói

Marcelo Costa de Andrade was a Brazilian serial killer who murdered 14 boys between the ages of 6 and 13 in Rio de Janeiro State between 1991 and 1992, drinking the blood of some victims after death. He believed killing young children before they could sin would send them directly to heaven and that consuming their blood would transfer their youth and beauty to him. He confessed after his arrest in 1992 and was found not guilty by reason of insanity, committed to a psychiatric institution. He was reportedly released at some point after 2003, drawing public outcry.