Andrew Weismann, the investigator dubbed as special counsel Robert Mueller’s “pit bull” by The New York Times, is headlining a virtual fundraising event for former Vice President Joe Biden.

Weismann will sit down with former New Jersey Attorney General Anne Milgram for a virtual “fireside chat” and fundraiser for Biden on June 2, according to the Biden campaign. 

Weissmann, a former Department of Justice lawyer, had been considered a “deputy” to Mueller during the Russia investigation. He played a key role behind the Justice Department’s charges against former Trump campaign chairman Paul Manafort and his deputy, Rick Gates. 

Weissmann was reportedly in attendance at former Democratic presidential nominee Hillary Clinton’s election night party in 2016, according to the Wall Street Journal. He also sent an email to former acting Attorney General Sally Yates praising her for refusing to defend President Trump’s travel ban in January 2017. 

“It’s no surprise that a guy who tried to take down the president through the sham impeachment would also help Joe Biden’s campaign,” Trump campaign communications director Tim Murtaugh told the Washington Examiner. “It doesn’t get any swampier than this: trying to stage a partisan coup against the president and then raising money for his political opponent.”

Donald Trump Jr. blasted the fundraiser, suggesting the media would meltdown if the political tables had been turned.

“Imagine how bad the mainstream media would meltdown if the DOJ lawyer that moved to dismiss the Flynn case left the DOJ and hosted a fundraiser for @realDonaldTrump?” he tweeted. “But because the media worships both Biden and Weissmann … crickets. Absolutely Pathetic!”

Wiessmann now works for MSNBC as a legal analyst after leaving the DOJ. He has been critical of President Trump’s policies and was supportive of the House Democrats’ impeachment of the president.

In December 2018, Trump criticized Weismann for his political bias.  

“Will Robert Mueller’s big time conflicts of interest be listed at the top of his Republicans only Report. Will Andrew Weissman’s horrible and vicious prosecutorial past be listed in the Report. He wrongly destroyed people’s lives, took down great companies, only to be overturned, 9-0, in the United States Supreme Court. Doing same thing to people now. Will all of the substantial & many contributions made by the 17 Angry Democrats to the Campaign of Crooked Hillary be listed in top of Report,” the president wrote.