Is Brown dropping dimes? Or is he just helping bring his own case to a close? (Haraz N. Ghanbari/AP)

In trying to convince U.S. District Judge Richard J. Leon to keep the motion secret, Justice Department lawyers argued that disclosing “the extent and timing of any potential cooperation ... could impede ongoing investigations by alerting persons suspected of engaging in criminal conduct of ongoing law enforcement activity and other information known to law enforcement.”

But the motion contains no revelations of special import. The closest tidbit to news is that Brown “has agreed to cooperate with the government in this and other criminal matters” and there likely “will be further discussions relating to cooperation.”

The most tantalizing part of that is the “other criminal matters.” Is Brown dropping dimes on his campaign bankrollers, his former council colleagues, the mayor? Anything’s possible, but it’s also possible that might refer only to the probe into Brown’s own campaign fundraising, in which several loose ends remain to be tied.

In other words, “persons suspected of engaging in criminal conduct” aren’t learning anything from these documents they didn’t already know.

Meanwhile, lawyers for a key figure in Mayor Vincent C. Gray’s 2010 campaign is saying ahead of his own sentencing that he “provided substantial assistance in furthering the investigation and prosecution of illegal activities.”

There are plenty of hints that the “upper echelons of the Gray campaign” have much to be worried about from Howard L. Brooks:

While Mr. Brooks acknowledges that his actions were wrong and illegal, we hope the Court will put his actions into context. It is clear that Mr. Brooks was not the mastermind behind the idea to provide this funding to Mr. Brown. ... These instructions came from the upper echelons of the Gray campaign, and certainly from above Mr. Brooks’ rank. ... He took direction from the top level campaign staff, and served as their liaison to volunteers. While Mr. Brooks played an important role in the campaign, he was not the “big fish” in the campaign or in the subsequent investigation.

But, again, they knew that already.