Barbara McQuade

Opinion contributor

One of the most intriguing recent court filings in special counsel Robert Mueller’s investigation came Friday in a brief arguing that Roger Stone’s case is related to the indictment against 12 officers from Russia's GRU military intelligence agency. They were charged with conspiring to defraud the United States by hacking, stealing and staging the release of email messages.

Stone was indicted in January on various charges of obstructing the House intelligence Committee investigation into Russian interference in the 2016 presidential election. Under local court rules, cases should be designated as “related” if they arise “from a common wiretap, search warrant, or activities which are a part of the same alleged criminal event or transaction.” Related cases are then assigned to the same judge.

Mueller argues that Stone’s case meets this standard because evidence in his case “was found in accounts that were subject to search warrants” that were executed in the GRU case, and because his alleged obstruction was "directed at a congressional investigation into conduct" that was the basis for the GRU indictment.

Evidence of Stone contact with GRU, WikiLeaks

One detail in the new filing jumps out. It says “the government obtained and executed dozens of search warrants on various accounts used to facilitate the transfer of stolen documents for release, as well as to discuss the timing and promotion of their release. Several of those search warrants were executed on accounts that contained Stone’s communications with Guccifer 2.0 and with Organization 1.”

Guccifer 2.0 is alleged to be a persona operated by the GRU, and Organization 1 is believed to be WikiLeaks.

This passage is revealing for several reasons. First, the filing discloses that the government has evidence of Stone’s direct communications with Russian intelligence and WikiLeaks. This revelation goes much further than the Stone indictment itself and establishes a direct link between Russia and Stone, a Trump campaign adviser.

Referring to these communications as “evidence” suggests that the special counsel considers the communications probative and relevant to proving Stone’s guilt. Whatever these communications are, we can reasonably conclude that they are incriminating.

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Second, the filing indicates that search warrants were used to obtain these communications. Search warrants can be used to obtain email and social media accounts, including the content of every email or Twitter direct message a user has ever sent or received. These communications would help Mueller determine whether Stone was ever in direct contact with WikiLeaks founder Julian Assange, as Stone claimed in August 2016.

In addition, a search warrant can be used to obtain emails from internet service providers doing business in the United States, even if the account user is overseas. If, for example, a Russian hacker were using a Gmail account, a search warrant to Google could provide every email ever sent or received on that account. And if the special counsel has obtained Stone’s email communications, it seems likely that he has also obtained the email communications of others, such as Donald Trump Jr., who has admitted to sending email messages to set up a meeting with Russians to obtain dirt on Hillary Clinton in June 2016.

Third, the phrase “to discuss the timing and promotion of their release” emphasizes that Mueller considers the conspiracy with which he has charged the Russian intelligence officers to include not just hacking and stealing emails, but also disseminating them. The GRU indictment provides a framework for adding as co-conspirators anyone else who conspired to promote the release of the stolen emails at a time that would be most beneficial to Trump’s campaign.

In fact, one batch of emails was released about an hour after news broke about the "Access Hollywood" tape in which Trump was heard disparaging women. If someone from the campaign suggested to WikiLeaks that stolen emails be released that day, that person could potentially be charged as a co-conspirator in the GRU case.

Strategic reasons to hold back on charges

Why, then, has Stone not been charged with conspiring with WikiLeaks or Russian intelligence officers? It could be that the evidence does not prove his agreement to engage in a conspiracy. Or it might be that Mueller is holding back on charging Stone as he investigates other targets.

When I served as a prosecutor, we sometimes strategically waited before charging every crime we believed we could prove. Mueller may be doing the same here for a number of reasons.

First, Mueller might want to avoid tipping off other targets until he has been able to gather all of the evidence against them. Second, by charging only the seven counts in the Stone indictment, Mueller doesn't have to produce to Stone discovery or evidence of other crimes while he continues to investigate the roles of other targets. Court rules would require such disclosure of charged crimes. And third, by holding back more serious crimes, Mueller has leverage over Stone to offer a plea and cooperation deal that is less severe than it would be if more crimes were charged.

If that's the case, then a superseding indictment with more charges, and maybe more defendants, may be in Stone’s future.

Barbara McQuade, a former U.S. attorney for the Eastern District of Michigan, is a professor at the University of Michigan Law School. Follow her on Twitter: @barbmcquade