What confuses you? DW has spent time in jail, was unemployed, has a history of domestic violence directed not just at women but also to members of his own family and is currently in jail for murder. Yes, I believe he is a hardened criminal who has associated with other hardened criminals for a long time.
JMO
Well, I can see someone learning a few ideas in county jail but not anything very sophisticated. Do you think that criminals specialize in the types of crimes they do?