The subpoena, issued to a dozen top officials in mid-October, marks Mueller’s first official order for information from the Trump campaign.

In the midst of all the chaos of the past month, special counsel Robert Mueller has been hard at work extracting information from members of the Trump campaign related to the investigation of their ties to Russia.

According to a new report from the Wall Street Journal, Mueller’s team issued a subpoena to Trump’s campaign in mid-October, marking the first official order for information from Trump campaign officials.

The subpoena, which seeks Russia-related documents and emails from more than a dozen top officials, came as a complete surprise to the Trump campaign, the Wall Street Journal reports, citing a person familiar with the case:

The subpoena, which requested documents and emails from the listed campaign officials that reference a set of Russia-related keywords, marked Mr. Mueller’s first official order for information from the campaign, according to the person. The subpoena didn’t compel any officials to testify before Mr. Mueller’s grand jury, the person said.

The subpoena caught the campaign by surprise, the person said. The campaign had previously been voluntarily complying with the special counsel’s requests for information, and had been sharing with Mr. Mueller’s team the documents it provided to congressional committees as part of their probes of Russian interference into the 2016 presidential election.

Trump’s team might have claimed to be complying voluntarily, but Mueller had a very good reason to suspect he did not have all the information: Jared Kushner.

Trump’s son-in-law is notorious for his “accidental” omissions of critical facts and assets from his reports to the government. Kushner left numerous details off of his security clearance form. And just today, the Senate Judiciary Committee — in the process of their own Russia investigation — said that Kushner failed to turn over all of the documents they requested.

Mueller, in short, was likely trying to get ahead of any slow-walking or secrecy that Trump’s team might use to obstruct his probe.

The Russia investigation cannot be deterred from its relentless pursuit of the truth. Mueller will get the answers — and so will the American people.