What happened to Dr Dre to turn him into a G thang?

so i was listening to so dr dre's rap, then i google about him, and i found out this guy used to be in a group when he was young, and in the group pic he was like cute and harmless, then i suppose something happened and made him get in this gangsta shyt. i noticed in ice cube's song no vasline, he mentioned eazye saw dre's azz and went in it without using vasline, is that why Dr Dre become such violent person