A primary day scheduled the day after Labor Day is causing state election officials to offer abysmal projections about voter turnout. But, a lack of interest doesn't translate to a lack of importance.

The Suffolk County district attorney's race drew five Democratic candidates and one independent after outgoing DA Dan Conley decided not to seek reelection. The District Attorney's office has the most direct hand in how abstract laws play out in the reality of people's lives. WGBH Morning Edition's Joe Mathieu sat down with Legal Analyst and Northeastern Law Professor Daniel Medwed to discuss the importance of DA races in Suffolk and Middlesex Counties. This transcript has been edited for clarity.

Joe Mathieu: What is the exact role — we should start with the basics here — played by county district attorneys in our state, especially as compared with the police or the attorney general, for that matter?

Daniel Medwed: District Attorneys prosecute criminal activity in their county, overseeing offices of varying sizes that decide whether to charge people with crimes, make bail recommendations, offer plea bargains, devise and execute trial strategy, defend convictions on appeal — a whole host of things.

But for one thing the police and the DA's office lack a formal affiliation. They have a very strong informal collaboration, of course, because the police investigate crimes, make arrests and then typically turn things over to the prosecution to make charging decisions. But there is no official link between the two. They're separate offices. Also, while the state attorney general's office typically handles complex sophisticated civil and criminal matters, the bread and butter of the criminal docket — homicides, sex offenses, larcenies, robberies — that falls within the purview of the county DA's office, which means that that office has a lot of clout and is very important.

Mathieu: So how unusual is it, with all that said, to have contested elections for DA?

Medwed: Surprisingly, at least when you look at it with a historical lens, these races are very sleepy affairs — they're not usually contested. It wasn't until the 19th century that prosecutors were elected in this country. It was part of the rise of Jacksonian democracy, and this desire to make public officials more accountable to the electorate.

And now about 45 states, including Massachusetts, elect their chief prosecutors. But people don't tend to pay much attention to these races. Usually it's name recognition or party affiliation that carries the day. One law professor named Ron Wright did a study of prosecutorial elections from 1996 to 2006. And get this, he found out that the incumbent won 95 percent of the time, and in the general election the winner ran unopposed 85 percent of the time. At least that's what it was like back in the day.

Mathieu: We're talking with WGBH News Legal Analyst Daniel Medwed about elections for district attorney. So how then do we rationalize what we're seeing here, from sleepy affairs to robust and well-covered primary battles in both Suffolk and Middlesex?

Medwed: That's a great question. On the one hand, we should view this through the national trends. People are paying more attention to criminal justice, whether it's mass incarceration, wrongful convictions, bail issues, people are focused on this, and I think a large part of it relates to the high profile shooting of African Americans by the police and the perceived failings of prosecutors to zealously pursue those cases.

So a number of prosecutors, veteran prosecutors, have been ousted by challengers based on the perception that they botched handling these cases. For instance, earlier this summer Robert McCullough, the long-time chief prosecutor in St. Louis County who famously failed to secure an indictment of the officer who shot and killed Michael Brown in Ferguson a couple years ago, he lost to a challenger from his left flank in the Democratic primary.

But on the other hand, it's often said, all politics are local. So, you look at Suffolk County, and Dan Conley stepped down after, I think, four terms. There would be a frenzy of candidates, a whole group of candidates, no matter what, because that's a very plum position, that's the Suffolk County DA position. But would we have five terrific Democratic candidates? I'm not so sure.

And then you look at Middlesex. You have the incumbent potentially being a little bit vulnerable because of some controversies in that office. There were some issues with shaken baby cases, the death of infants and toddlers and a little bit of controversy surrounding that.

Mathieu: So are you making any predictions about the outcomes of either of these primaries?

Medwed: I'll stay out of that. Let's leave that to WGBH News' Peter Kadzis and Adam Riley and those folks, but I will say this: if you're going to the polls and you're thinking about voting for a district attorney, try to take some time to do some research and make an informed choice. It's a very important election.