For two hours and 36 minutes, William J. Bratton sat before the New York City Council, his hands often posed flatly on the table before him, his Boston accent echoing through the packed hearing room as he responded to a succession of questions on his plans to overhaul officer training.

If some on the Council arrived on Monday angry about the death of Eric Garner and primed for the acrimony that has accompanied police hearings in years past, they instead found a police commissioner apparently channeling the very techniques of de-escalation and conflict resolution that, he testified, all city officers would soon be taught.

Yes, he agreed, the department had been too aggressive in minority neighborhoods, engaging in activity that was “not necessary” and eroding trust. Yes, he said, officers had become too focused on numbers, eschewing the discretion they had on whether or not to make an arrest, a key part of the job. “There was a need for a fundamental shift in the culture of the department,” he said, voicing a sentiment shared by many on the Council.

“That acknowledgment is significant,” the Council speaker, Melissa Mark-Viverito, told him.

It was the third time Mr. Bratton was before the Council since returning to the police commissioner’s job this year, but nine months into his new tenure, it was the first time he found himself facing an oversight hearing focused all but explicitly on his mandate from Mayor Bill de Blasio: to remake the Police Department’s relationship with communities distrustful of its officers.