RIO DE JANEIRO, Safar 19, 1436, Dec 11, 2014, SPA -- A man arrested by police in Rio de Janeiro on suspicion of murder has confessed to killing 42 people over the past decade, making him potentially one of the country's most prolific serial killers, Reuters reported. Sailson Jose das Graأ§as, 26, who was arrested on Wednesday, told reporters at a police station in the state of Rio that he killed for pleasure and the accompanying adrenaline rush. He said he also operated as a killer for hire. He said his preferred victims were white females, whom he strangled. Among the 42 victims, 39 are thought to be women. The news comes just months after a security guard confessed to killing 39 people, mostly homeless people and transvestites, in the Brazilian city of Goiania. -- SPA 21:28 LOCAL TIME 18:28 GMT www.spa.gov.sa/w