Suffolk County District Attorney Dan Conley announced Thursday he will not seek reelection in November.

Throughout his 16 years in office, Conley has overseen high-profile cases such as the double murder trial of former New England Patriots tight end Aaron Hernandez and the death of 2-year-old Bella Bond. He also led efforts to exonerate several men who were wrongfully convicted prior to his tenure, and implemented the commonwealth's first conviction integrity program to help overturn and prevent wrongful convictions.

Conley also served as a Boston city councilor for eight years and unsuccessfully ran for mayor in 2013.

Conley spoke with WGBH News' Phillip Martin about his tenure, the impact of the Black Lives Matter movement, and his decision not to run for reelection in November. A transcript of their conversation is below and has been edited for clarity. Click the audio player above to listen to this interview.

Phillip Martin: Why now? Why have you decided to call it a day, if you will?

Dan Conley: Well it's, it's an exercise that I've gone through really every four years, you know, whether or not I am going to seek another term. And I did it again this time. It had been 16 years that I had been district attorney and I had accomplished a lot. The office is really, I believe, a national leader in so many areas. And I had been in a city council for eight years, as well. So you put it all together, it's about 25 years in elected office. Actually this fall, my wife and I will be celebrating our 25th wedding anniversary. She's — during our entire marriage I've been an elected official, so that that takes a toll on a family. My kids were toddlers, really, when I took this job and they're in college now, so you know, a lot has happened in the last 16 years, and you know, much of it very, very positive. I enjoy the job tremendously. I've got a great staff and I'm going to miss, you know, working with them on a daily basis. But I also felt that if I'm going to do one more thing professionally, you know, whether it's in the law, or in the nonprofit world, or in academia or something like that, this is the time to do it.

PM: Every case is important, but is there a particular case that you solved that you prosecuted that brings you more satisfaction than others in terms of feeling that you got someone really, really bad off the street?

DC: No one deserves to die by violence. So we prosecute cases where the victim was a well-known gang member who was carrying a firearm at the time he was murdered and was known to have been involved in drug trafficking, let's say, equally as hard as the young kid in a party like Trina Persad, who gets caught by gunfire in a random act of violence. Having said that, I guess if I had to single out one case, because of the magnitude and the depth and the breadth the loss ... it would be the homicide of Roseanna Kamea. She was a beautiful young woman. She came to the United States to put her life on hold to make sure that her profoundly disabled son had medical attention. The family was split up and she was brutally murdered and sexually assaulted. And when we were able to win a conviction in that case, it meant a lot.

PM: Black Lives Matter, concerns about police abuse, shootings that have been questionable in many cases. I'm wondering how Black Lives Matter as a movement has impacted you as district attorney for Suffolk County.

DC: In my tenure, I've had somewhere between, I don't know, 15 and 20 police-involved shootings that have resulted in deaths. And we have set, I believe, a national standard, a high bar that no prosecutors' offices have exceeded in the United States, where we conduct the most meticulous, the most thorough, the most documented investigation of police-involved shooting. And then, I always meet with the family first to explain to them what our process is going to be. I then, with my senior team, you know, we evaluate and scrutinize and analyze what evidence has been gathered over and over again to apply the law that the courts have given us and apply it to the facts as we have determined them and then make a decision whether or not the officer or anyone should be charged criminally for the death. Now, in those — I don't have the exact number, let's say 15 times that I've done this, I have concluded that the officers have acted with justification. I have been, on one or two occasions, criticized, 'Well how can you have looked at 15 cases and not charged one police officer?' And it kind of goes back to my last answer, is that we would never charge anyone, police officer or not, with a crime for which we do not have a good-faith basis that we can prove them guilty beyond a reasonable doubt. And in the cases that I've looked at and analyzed, it's not really even a close call. The officers have used deadly force as a last resort.

PM: What are your plans? What do you hope to accomplish in the post-district attorney period?

DC: Well I admired the way David Ortiz retired, and I think I could have certainly done another term. But I always felt that it's going to be pretty cool to go out on your own terms and to leave when you can still hit the fastball, so to speak.