The Park Maniac delves into the story of one of Brazil’s most famous serial killer: Francisco Pereira. In the 90s, the motorcycle courier was accused of attacking 21 women, murdering ten of them. The killer's story and the details of his psychopathy are revealed by Elena, a rookie reporter, who sees in the investigation of the crimes committed by the maniac the great chance to leverage her career. While Francisco continues to live free, skating through parks and attacking women, his fame in the sensationalist media grows, generating terror in the capital of São Paulo.