A man put a police officer in a chokehold before a bystander came to his aid during a struggle at a New Jersey mall Friday evening, police said.

Deptford Township police said officers were sent to the Deptford Mall just after 7:30 p.m. Friday on a report of a disorderly man allegedly harassing patrons.

A uniformed officer found the man on the second floor of the mall and asked him to leave multiple times but he refused to do so and "allegedly became confrontational," eventually taking a fighting stance, police told Fox 29 .

As the officer tried to arrest him on defiant trespass and disorderly conduct charges, a struggle ensued during which the man was able to put a chokehold on the officer, "effectively cutting off" his blood and oxygen supply, police said.

During the struggle, a bystander interceded and helped the officer escape the chokehold and get the man into handcuffs, police said. The officer was treated by county emergency medical personnel for minor injuries, police said.

The bystander has been identified as Robert Fitzpatrick, 6ABC reports.

"I had seen it escalating as I was going into the store. I heard a loud bang and I asked the manager to watch my two children," said Fitzpatrick, who teaches at Penns Grove High School.