Four Republicans Senators asked the Federal Bureau of Investigation Friday to provide them with details about the campaign finance charges brought against conservative filmmaker Dinesh D’Souza.

Sens. Mike Lee (R-Utah), Chuck Grassley (R-Ia.), Jeff Session (R-Ala.) and Ted Cruz (R-Texas), each a member of the Senate Judiciary Committee, in a letter addressed to FBI Director James Comey asked whether there was some degree of targeting involved in the campaign finance charges brought against D’Souza.

“The Washington Post and other news outlets reported that the U.S. Attorney’s Office said that the investigation that led to the [D'Souza] indictment began as a result of a ‘routine review by the FBI of campaign filings with the FEC of various candidates after the 2012 election,’” the letter said. “The articles, however, did not provide any details regarding the scope and methodology of these routine reviews.”

The senators questioned whether targeting played a role in the D’Souza investigation, adding that to “dispel this sort of public perception that Mr. D’Souza may have been targeted because of his outspoken criticisms of the president, it is important for the FBI to be transparent regarding the precise origin of this investigation.”

The letter then asked several questions of the new FBI director.

First, is it true that the FBI conducts “regular, perhaps random review of campaign filings”?

It continued, asking that the FBI explain “all methods by which a review of campaign filings may be initiated,” requesting further that the agency mention any other federal agencies that may have participated in such reviews.

“Specifically, the senators asked how and why the D’Souza review was initiated, as well as “what criteria involved in this particular review led to the suspicion that warranted further inquiry.” The lawmakers also asked how many campaign filings the FBI has reviewed in the past five years, how many agents were assigned to such matters, and when the FBI began “routinely” reviewing campaign filings,” the Washington Examiner’s Byron York notes. “The senators made no assertion one way or the other about D’Souza’s guilt or innocence in the case. But they clearly want to know if the D’Souza indictment resulted from a process that was truly random.”

Here’s the full letter:

(H/T: Mediaite)

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This post has been updated.