WASHINGTON — The Trump-era Justice Department’s attempt to identify the person behind a Twitter account devoted to mocking Representative Devin Nunes, Republican of California, stemmed from a U.S. Capitol Police investigation into a purported online threat to Senator Mitch McConnell, not to Mr. Nunes, according to two law enforcement officials.
The account by the officials, which dovetailed with earlier reporting by CNN, filled in some gaps about the Trump Justice Department’s issuance of a grand-jury subpoena in November in an effort to identify the user behind the @NunesAlt parody account. But much about the issue remains murky.
On Monday, a federal judge unsealed court filings showing that Twitter had balked at complying with the subpoena, questioning whether it was an abuse of power to go after a critic of a close Trump ally. The social media company noted that Mr. Nunes and his lawyer had filed lawsuits seeking to identify his online critics, including the @NunesAlt account.
While Twitter routinely complies with the legal process for information about users, it viewed this request with suspicion.
Twitter filed a motion to quash the subpoena in March after it sought more information about the basis for it and the Trump Justice Department provided few additional details, like identifying any particular posting that constituted a threat. The Biden Justice Department then withdrew the subpoena, but the Capitol Police have said their overall investigation into an online threat was continuing.
The new information suggests that Mr. Nunes, whose office has not responded to a request for comment, may not have had any role in the subpoena. The two law enforcement officials, speaking on condition of anonymity, said it stemmed from an online threat last fall to Mr. McConnell, a Kentucky Republican who was the majority leader at the time, when he drew the ire of liberals by rushing to confirm Justice Amy Coney Barrett to the Supreme Court just before the election after the death of Justice Ruth Bader Ginsburg.
The offending post had since been deleted or removed, one of the officials said. The other said that the primary offending post had not been written by the user of @NunesAlt, but that the account may instead have amplified it.
In a Twitter direct message, the user of @NunesAlt expressed continued bewilderment, writing, “I’ve been searching my tweets also for anything that could be interpreted as threatening and haven’t been able to find anything.”
The user also said that he or she had also tweeted about Mr. McConnell a fair amount and that it was possible some of those posts had been deleted. The user also noted that there had been online joking in October about photographs showing Mr. McConnell’s hands bruised and discolored, and pointed to a post riffing on that topic that is still available.
Another Twitter user had posted a picture of Mr. McConnell’s discolored hand and written: “This confirmation is totally illegitimate because Mitch McConnell is an undead rotting corpse. Undead votes don’t count. #DeatherMovement.” The @NunesAlt user retweeted that, adding: “When Mitch McConnell does the ‘pull my finger’ trick, you get to keep the finger.”
In a Twitter direct message, the @NunesAlt user wrote: “I seem to remember making more than one off-color joke about this. There were zombie jokes etc going around. Maybe the ‘death’ theme of the jokes could be distorted to seem threatening.”
Adam Goldman contributed reporting.