"The events of the past month are as bad as I've seen it in 30 years," Shea said.
To say it's been a challenging first six months on the job for Shea would be a vast understatement.
In that short period of time, he's had to steer the nation's largest police department through unprecedented times.
There has been explosive civil unrest and sweeping police reforms - converging in the midst of a deadly pandemic.
And along the way, his department's reputation has taken a hit.
"Somehow the police have become the enemy...and I don't think that's right and I don't think it's true either," Shea said. "But that narrative is certainly out there and probably over time we've contributed to that narrative through our own actions."
Just last Sunday in Queens, an NYPD officer was caught on camera putting a man in a chokehold.
Shea said his initial reaction when he saw that video is something he probably can't repeat.
The NYPD has had six years to reform ever since the death of Eric Garner.
It is now illegal for a police officer to put someone in a chokehold.
"I think cops are frustrated by the incident and the nature of our work is that we build trust so slowly and it's taken away quickly," Shea said.
Under new reform regulations, the NYPD's reaction was swift. The officer was identified and suspended without pay, the video was released and an internal affairs investigation was launched.
"It's new rules, we have to recognize that, we have to be quicker, but we have to be right and that's what I try to balance," Shea said.
Still, the troubling incident has left another stain on a department struggling to build trust with an increasingly skeptical public - especially in predominantly Black and Brown neighborhoods.
"They employed many of the tactics that have been put into place over the last six years -- de-escalation, talking to the people -- but ultimately we're going to be judged by five seconds at the end, and you're right, you're 100% right, we cannot for over 20 years put somebody in a chokehold, and that was by any definition," Shea said. "We have circumstances sometimes in the heat of the moment, something happens that shouldn't happen, I think this was not that case, I think this was a clear cut."
That chokehold came after weeks of racial unrest and protests sparked by the death of George Floyd.
The demonstrations often pitted protesters against police and sometimes with violent results.
Video showed some officers clearly overstepping boundaries. But the violence went both ways - with officers also becoming targets.
"It's a tough line of work because you deal with such emotion," Shea said. "I think they did an amazing job and people will hear that and I'll take criticism. There were mistakes but it was a small number, I would say that every use of force is not wrong, I would remind people of that and I would also remind people that I still have officers recovering at home from a multitude of injuries."
But Shea also said a number of officers still on the force are repeat offenders of questionable conduct. Some have been the focus of civil lawsuits that have led to millions in settlement payouts.
"I think that it needs a deeper look," Shea said. "Is it an officer that is perhaps just making bad decisions and perhaps should not be an officer anymore?"
"This is where we, and I mean me, have failed, because we have had a risk management bureau for about five years now, so we already have that in place," She said. "Is it perfect? No. Does it serve as a warning system? Yes."
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