Minutes after the bagpipes faded and he took the oath of office on Thursday, Police Commissioner William J. Bratton signaled that he intended to shift the nation’s largest police department away from an aggressive style of patrolling New York City that had alienated many minority residents.

In his first policy message to the city and the police force he now commands, Mr. Bratton said that the tremendous strides the department had made in reducing crime should long ago have given way to fewer confrontational encounters between the police and the public.

“Crime is down to such extraordinarily low levels in this city versus where it was that there is an expectation — or there should be an expectation — that the intrusion of police into citizens’ lives should also diminish,” he told reporters after being sworn in. “But we had the reverse happening.”

A day after he officially took over the department on Wednesday in a private ceremony, Mr. Bratton said it was unfortunate that relations between the police and the community were marked by “disconnect” and “alienation.”