Ademir Oliveira Rosário (born 1971), known as The Cantareira Maniac (Portuguese: Maníaco da Cantareira), is a Brazilian serial killer and serial rapist who gained notoriety for murdering two teenagers in 2007. The crimes were committed after his release on probation from a psychiatric clinic, where he had been interned for a 1991 manslaughter conviction and other charges. For the latter crimes, he was convicted and sentenced to 57 years imprisonment.