Even though he was a halfway decent cop when with the Metro-North and New Haven departments, once in charge at stamford he headed an organization notorious for ninny state policing, basically arresting people for sneezing, farting, telling someone to fuck off, being in the wrong place because they were sick, usw. Additionally, it was common practice from members of the stamford pd to take items from seized property, and evidence and give them to people in lieu of cash payment, as some members did to my stepfamily when they rented out part of their townhouse in Greenwich.
Once in providence at mayor sissyweenie's invitation, he upheld new practices which included not allowing clergy to visit prisoners, which along with at wall's practices led to criminalization of people while in custody because of their religion. Along with allowing ppd members to run amok and detain and arrest them for trivial matters, as he had done in stamford, led to hostility against the police.
When esserman returned to New Haven he had been chewed up and shit out by providence, and people in New Haven did not research thoroughly his actions in providence before rehiring him.