How many people does it take to create or, conversely, eliminate a systemic problem? 100? 10? All of them? None of them? A few?

It's a dilemma for Ferguson, Missouri, which has to figure out how to respond to the scathing Department of Justice report on civil-rights violations in the St. Louis County city. (Conor Friedersdorf curates some of the more appalling revelations from the 102-page document here.) Given the scale of the issues the report documents, and given how many local officials were part of the system, it's hard to figure out where to start. Although Attorney General Eric Holder has said he would dismantle the Ferguson Police Department if necessary, starting over from scratch is understandably not a first choice. Until this week, one of the biggest challenges was that the high-ranking city officials charged with fixing these problems were the same people who'd overseen and fostered their creation. Now many of them are leaving.

If you were going to pick out four major figures who come out poorly in the report, Municipal Judge Ronald Brockmeyer, City Manager John Shaw, Court Clerk Mary Ann Twitty, and Police Chief Thomas Jackson might fit the bill. And over the course of the last week, all four have announced their departures.

First, Ferguson announced last Thursday that Twitty had been fired for sending racist emails—though the DOJ report also found she was central to the operation of the city's slanted justice system, wielding as much power as Brockmeyer.

Brockmeyer resigned Monday. He'd been municipal judge for a decade, and DOJ detailed how he turned the city's justice system into a cash machine, instituting elaborate revenue-generating operations with fines and fees. In 2012, a member of the city council complained that Brockmeyer "does not listen to the testimony, does not review the reports or the criminal history of defendants, and doesn’t let all the pertinent witnesses testify before rendering a verdict.” Shaw acknowledged receiving the mixed reviews, but still recommended Brockmeyer be reappointed: “[i]t goes without saying the City cannot afford to lose any efficiency in our Courts, nor experience any decrease in our Fines and Forfeitures.” Brockmeyer also fixed tickets in Breckenridge, a nearby city where he also serves as municipal judge, and asked that his own tickets be fixed.

Then, on Tuesday night, Shaw resigned as city manager. The move was apparently not expected, and surprised those in attendance at the city council meeting where it was revealed. Shaw had run the city since 2007 and was more powerful than the elected mayor, but had remained mostly out of the spotlight throughout the saga of Michael Brown's death, the ensuing protests, and the grand jury's decision not to indict Officer Darren Wilson.

The last man standing, surprisingly, was Chief Jackson. Jackson's departure has been the subject of speculation since at least October, when it was reported he'd be leaving as part of an agreement between the city and the Justice Department. But it wasn't until Wednesday afternoon that he announced his resignation.

These steps still leave much work to be done. In a devastating, detailed report from St. Louis in September of last year, The Washington Post's Radley Balko laid out how the checkerboard of jurisdictions around St. Louis profit from people of color and the poor, often precisely because there are so many of them with disconnected justice systems. And as the Huffington Post noted last week, many of the neighboring municipalities seem to have reacted to the DOJ report with little more than a shrug. Brockmeyer, for example, remains a judge in Breckenridge, a prosecutor in three other towns, and a criminal-defense attorney. It will take more than a handful of personnel changes to fix what ails Ferguson, and fixing Ferguson is only the first step in addressing the regional and national problems it has come to exemplify.