Responses
https://www.mangago.zone/read-manga/when_the_killer_falls_in_love/
https://www.mangago.zone/read-manga/dangerous_convenience_store/
https://www.mangago.zone/read-manga/when_the_yakuza_falls_inlove/
https://www.mangago.zone/read-manga/madman_combo/
https://www.mangago.zone/read-manga/gokusen/
These are some I have read and there's a list of bl mafia webtoon you can check that out
https://www.mangago.zone/home/mangalist/206/
mafia / crime:
https://www.mangago.zone/home/mangalist/2448175/
some gangster/mafia colored webtoon
bl or non bl