From the article:
“Bullies might be more likely to engage in risky or illegal behaviors in adulthood. When they grew up, bullies were more likely to have been convicted of felonies and to have abused drugs, and they actually tended to be poorer and lonelier than their former victims. However, when researchers controlled for childhood hardships like divorce or psychiatric problems, they found that a bully’s situation didn’t look quite as dim. In other words, bullies tended to have more troubled childhoods—and that may explain both their bullying and the greater likelihood of engaging in illegal behaviors down the road. ”
https://greatergood.berkeley.edu/article/item/bullied_children_grow_into_wounded_adults