Former FBI General Counsel James Baker testified Thursday that the bureau examined the data alleging a Trump connection to the Kremlin-linked bank, and discovered that "there was nothing there."
Mook was called to the stand for testimony by Michael Sussmann’s defense Friday.
During a cross-examination by government prosecutor Andrew DeFillippis Friday, Mook was asked about the campaign’s understanding of the Alfa Bank allegations against Trump and whether they intended to publish the data to the media.
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Mook said he was first briefed about the Alfa Bank issue by campaign general counsel Marc Elias, who at the time was a partner at law firm Perkins Coie.
Mook said that he was told that the data had come from "people that had expertise in this sort of matter."
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Mook said the campaign was not totally confident in the legitimacy of the data, but had hoped to give the information to a reporter who could further "run it down" to determine if it was "accurate" or "substantive."
He also said he discussed whether to give the information to a reporter with senior campaign officials, including campaign chairman John Podesta, senior policy advisor, now White House National Security Adviser Jake Sullivan, and communications director Jennifer Palmieri.
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"I discussed it with Hillary as well," Mook said.
"I don’t remember the substance of the conversation, but notionally, the discussion was, hey, we have this and we want to share it with a reporter," Mook said.
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The government asked Mook if Clinton approved "the dissemination" of the data to the media.
"She agreed," Mook testified.
Mook later said he "can't recall the exact sequence of events," when asked if he shared the idea to give the Trump-Alfa Bank allegations to the media with Clinton before or after the decision was made.
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"All I remember is that she agreed with the decision," Mook testified.
Sussmann has been charged with making a false statement to the FBI when he told Baker in September 2016, less than two months before the presidential election, that he was not doing work "for any client" when he requested and attended a meeting in which he presented "purported data and ‘white papers’ that allegedly demonstrated a covert communicates channel" between the Trump Organization and Alfa Bank, which has ties to the Kremlin.