When I had the job of police commissioner, 20 years ago, I was more sensitive, more cognizant of complaints and concerned about public opinion. I've learned to do what I think is the right thing. That lessens the impact of criticism. You get used to a pressurized environment and expect it every day.

You can be stopped if a police officer reasonably suspects a crime is about to be committed, is being committed or has been committed. Every law enforcement agency does it. It's essential to policing.

I liked the military life. They teach you self-sufficiency early on. I always say that I learned most of what I know about leadership in the Marine Corps. Certain basic principles stay with you - sometimes consciously, mostly unconsciously.

I never think of the word legacy. It doesn't mean anything. You do the right thing, in my judgment, and things will work out. That's what drives me. I'm not looking for legacy or history books or whatever. I know what we've done here has saved a significant number of lives. The burden is not on me. It's on the politicians who made the decisions to limit what we're doing. They're the ones who are going to pay a price, in my judgment, if crime significantly increases.

If you go into any department store these days, your picture is probably taken 30 times. In London there are 500,000 cameras in public spaces. You have no expectation of privacy in public spaces.

When I had the job of police commissioner, 20 years ago, I was more sensitive, more cognizant of complaints and concerned about public opinion. I've learned to do what I think is the right thing. That lessens the impact of criticism. You get used to a pressurized environment and expect it every day.

I've been the longest-serving police commissioner in the history of the department, but it's time in my life to move on. I'm ready for new adventures, new challenges.