I know in counties like Colombia, Brazil and Norway. I did some research and I found out about the cases of Arnfinn Nesset in Norway who killed at least 22 people in the early 80s and was released in 2004. Abel Mikaelsen Klemmensen in Greenland who killed 7 people at a party in 1989 and was released in 2015 and Australian criminal Berwyn Rees who was paroled in 2019 after serving 39 years in prison for killing three people including a police officer between 1977-1981. British Child killer Simon Smith who murdered three of his infant children between 1993-and-1997 who despite being sentence to a whole life term later applied against this sentence and it was reduced to 24 years-to-life and was released in 2020. Teenage serial killer Warren Harris in America who killed four people in the 1970s and given parole in 2024.