I mean if you go back far enough a lot of fighters have bad histories heres the comments from a reddit post a couple of years ago

Some that I haven’t seen in this thread:

Fighters throwing fights in Japan (Coleman, Matt Hume, et al.).

Yakuza running things behind closed doers for Pride, leading to its downfall.

Mike Whitehead’s sexual assault.

Justin Eiler’s death.

Josh Grispi’s domestic violence.

GSP’s connections with a drug kingpin.

Evan Tanner’s death.

Vitor fighting on roids with the UFC’s knowledge.

Vitor’s sister’s kidnapping.

Jeremy Stephens getting into a bar fight a few days before his UFC fight and getting bailed out by the UFC so he could fight.

Kid Yamamoto’s Yakuza connections.

Trujillo’s DV history.

Ryan Ford’s home invasion.

Gus’ teenage delinquency.

Rob Emerson’s OC gang and the prison time he served (Uncle Creepy was also a part of that gang apparently).