NEW YORK (CBSNewYork) — Mayor Bill de Blasio has vowed that police officers will be trained to use the least possible amount of force.

As CBS2 Political Reporter Marcia Kramer reported, the announcement came as a new video surfaced of the controversial arrest of a theft suspect in Sunset Park, Brooklyn – raising questions about the behavior of some NYPD officers.

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A new class of police officers took the oath of office on Thursday amid new and intense pressures to avoid improper use of force while making arrest.

“A lot has changed over the years; a lot of recognition about how to deescalate conflict,” Mayor de Blasio said. “These new officers are going to be trained in a way that’s more effective. They’re going to be trained how to get the job done with the least possible use of force.”

The swearing-in came as the Civilian Complaint Review Board said excessive force was used in the mistaken-identity arrest of former tennis star James Blake outside the Grand Hyatt New York in Midtown last month.

Also making headlines this week was a new and disturbing video showing the arrest of a Staten Island man who was accused of stealing an emergency medical technician’s cellphone.

The EMT was seen on surveillance video in a Sunset Park bodega, roughing up the man he said he caught breaking into his car. Police officers at the scene did not stop the EMT, and appeared also to use some force to arrest the suspect.

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“It is a matter that is the subject of an Internal Affairs investigation,” police Commissioner Bill Bratton said.

Police experts said the surveillance video in the bodega showed just how difficult it is to train officers in the use of force. Each situation is different and hard to predict, according to experts.

For example, experts pointed out that there was no way the officers could have known the EMT would attack the man who took his cellphone.

“You can have the most and best training in the world,” said former NYPD officer Joseph Giacalone, now of John Jay College, “but when you’re involved in it, each situation is dynamic, and things can happen in a split second before the officer even realizes what’s happening.”

Still, there is one key question – can officers be trained not to use force?

“You can’t train people not to use force,” Giacalone said. “But you can train people to maybe think a little bit more, or take a step back. Police work is inherently dangerous, and you know, any officer that waits too long could cost him or her their life.”

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Some police experts worry that the intense focus on the use of force could have an adverse effect – causing some to hesitate to make arrests, and causing others to stay in their patrol cars and do nothing.