By Greg Argos

PHILADELPHIA (CBS) — Richard Ross joined the Philadelphia Police Department in 1989 and rose through the ranks to become police commissioner before he resigned Tuesday evening. Ross was sworn in as Philadelphia’s top cop on Jan. 5, 2016.

He held the department’s top job for less than four years. But in that time, he dealt with some major situations with the men and women tasked with keeping Philly safe.

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“We need to be more responsive and more accountable to all of our neighborhood,” he said after being sworn in.

His first test came just two days later, when Patrol Officer Jesse Hartnett was nearly executed by a man in flowing Muslim garb. The incident was captured on camera and gained international attention.

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“According to him, he believed that police defended laws that are contrary to the teachings of the Quran,” Ross said following the incident.

Ross led the Philadelphia Police Department through a time of increased violence. The city’s homicide rate is the highest in over a decade.

In 2018, 353 people were killed — an 11% increase compared to 2017.

Now, with more than four months left in 2019, more than 203 homicides have been committed.

“Another night of senseless carnage in the city but we’re going to continue doing what we do,” the former commissioner said.

His department has also faced intense scrutiny with two other cases.

The first came from April 2018, when Philadelphia police arrested two black men at a Rittenhouse Starbucks, after a manager there called 911 saying the men were trespassing.

Ross backtracked on his initial defense of what happened.

“I should have said the officers acted in the scope of the law. And not that they didn’t do anything wrong. Words are very important,” he said at the time.

More recently, in June, the former commissioner fired 13 officers for alleged racist, sexist and inappropriate posts on Facebook.

Seventy-two officers were initially placed on administrative leave after a watchdog group discovered the controversial posts from officers in Philadelphia and other cities around the country.

“It really makes me sick because we are in a position to know better,” Ross said following the discovery.

But perhaps Ross’ ultimate challenge came less than a week before his resignation when a gunman opened fire, shooting six of his officers.

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The former commissioner himself negotiated with the shooter, ending the largest mass police shooting in the department’s history after nearly eight hours, miraculously without anyone killed.

“There are many heroes from last night, probably too many to mention by name,” Ross said to reporters following the hourslong standoff.

The department’s handling of the shooting earned the commissioner this title from Mayor Jim Kenney, who now just accepted his resignation.

“I’d like to take this opportunity to introduce the best police commissioner in America,” Kenney said in regards to the former commissioner after the shooting.

A lawsuit obtained by CBS3 Tuesday alleges that Ross was aware of sexual harassment allegations made by two female officers and did not take action. In one instance, the lawsuit alleges Ross vowed not to act on one of the plaintiff’s complaints because he was angry that she had broken off an affair with Ross that lasted from 2009 to 2011.

Eyewitness News reached out to Ross for comment Tuesday night but did not receive a response.