OHIO — Shadowy outside groups dropping cash into political races has been a recurrent theme this year in Ohio, as in other swing states. On Friday, ProPublica’s Justin Elliott “pull[ed] back the curtain a bit,” as Elliott put it, on one such mysterious group—a Columbus-based nonprofit that has spent more than $1 million since May in Ohio’s US Senate race (the most expensive Senate race in the country) and, as a 501(c)(4), is not required to disclose its donors.

The nonprofit, called Government Integrity Fund, has purchased statewide television ad time throughout the late spring and summer to pummel Democratic incumbent Sen. Sherrod Brown, while praising his GOP opponent, Ohio Treasurer Josh Mandel.

Elliott was able to shed a little light on the murky Government Integrity Fund—including the name of its chairman, who is an Ohio lobbyist—thanks to “previously unreported documents filed with an Ohio television station,” Cincinnati NBC affiliate, WLWT, which has run the group’s ads. Wrote Elliott:

The documents identifying [Tom] Norris as the chairman of the Fund are public because of a Federal Communications Commission rule requiring TV stations to keep detailed records about political advertisers. The files can be valuable, offering a look at exactly who is spending and how much. Until recently, the documents were only available by physically traveling to stations. ProPublica’s Free the Files project has spotlighted the issue and this summer the FCC passed a rule requiring the stations in the nation’s top markets to upload the files to a government website.

(CJR, too, has spotlighted the issue and done its own reporting on access to and contents of public inspection files).

In other words, Elliott got his story by looking at publicly available (now, online) documents in which he found a few bits of information about a group whose name appears at the end of ads seen by many, many Ohioans but about which little is known. He got the story, that is to say, by examining documents that Ohio news organizations could and should routinely inspect.

In addition to reporting that the group is run by Norris, Elliott discovered that Norris “last year hired a top Mandel aide, Joel Riter, to work” at his lobbying firm. Per Elliott:

Riter’s role in the Government Integrity Fund, if any, is not clear. The former Mandel aide declined to say whether he is involved with the group that is chaired by his current boss and running ads in support of his former boss.

Riter declined to comment to ProPublica, and neither Norris nor the Mandel campaign responded to ProPublica’s request for comment. Elliott also linked to an earlier Dayton Daily News investigation about Mandel hiring former campaign workers for state jobs, which triggered a Democratic lawmaker to file an ethics complaint against Riter, contested by the former aide.

Several Ohio media outlets picked up Elliott’s story, as ProPublica encourages news organizations to do, and some added to it or ran with a different version, but others—including The Blade of Toledo and the Akron Beacon Journal, by my searching—took a pass. They shouldn’t have.

The Cincinnati Enquirer ran Elliott’s story on Friday, adding its own analysis that the group had spent “roughly $140,000 on 155 spots on Cincinnati TV stations.”

The Cleveland Plain-Dealer and the Dayton Daily News both ran a story compiled by the Associated Press (headline, “Ex-Mandel aide tied to lobbyist behind Senate ads”) that also notes in the lede the group’s “business links to a one-time aide to Brown’s opponent.” The AP’s Julie Carr Smyth was able to get Riter to say he had no involvement with the Government Integrity Fund or the advertising it sponsored.

The Columbus Dispatch, Canton Repository, and Kent State’s and Ohio Public Media’s WKSU radio station also picked up part or most of the ProPublica story.

There’s a “gold mine of data,” as Steven Waldman wrote for CJR in May, in these public inspection files, where Elliott unearthed his nuggets. News organizations in Ohio and other advertising-flooded swing states should get familiar with the files—and fast.

Correction: The original version of this story misspelled the last name of ProPublica’s Justin Elliott. CJR regrets the error.

T.C. Brown covered government and politics in the Ohio Statehouse Bureau for The Plain Dealer of Cleveland for more than 17 years, and he has also written for other local, state and national publications. Brown is a founding partner in Webface, a social media communication company.