48-year-old serial killer Tomas Maldonado Cera mutilated his victims by removing their fingers and using these to create devil-worshipping symbols on their bodies.
Stars and hexagrams were also exhibited on the corpses. In the places where the bodies were found, satanic writings and symbols were found in the sand. Most of the victims were killed before October 31, the date on which Halloween is celebrated.
Nicknamed 'El Satanico' (The Satanist), Maldonado was arrested in 2019 in Barranquilla, Atlantico, Columbia, after the body of Brenda Parajo Bruno was found in a woodland area.
More here: https://www.mirror.co.uk/news/world-news/satanic-serial-killer-used-fingers-14004101
And here: https://en.wikipedia.org/wiki/Tom%C3%A1s_Maldonado_Cera
And here: https://gravereviews.com/2020/08/13/tomas-maldonado-cera-the-satanist/
"Authorities then quickly linked him to the deaths of four men and another two women."
This is how a group turns into a lone serial killer.