Alexander van der Zwaan, a Dutch lawyer who pleaded guilty to lying to special counsel Robert Mueller’s team, was sentenced to 30 days in jail Tuesday morning. He’s the first person charged in Mueller’s investigation into the Trump campaign’s ties to Russia to be punished by a court.

District Court Judge Amy Berman Jackson also ordered van der Zwaan to pay a $20,000 fine. Van der Zwaan was contrite at his sentencing hearing in federal court in Washington, DC.

“What I did was wrong,” he said. “I apologize to the court for my conduct.”

Mueller’s team didn’t ask for a specific sentence for van der Zwaan, whose attorneys had asked Berman Jackson to keep their client out of jail.

Berman Jackson said she considered only fining van der Zwaan.

“I’ve thought about it, but I just can’t say, ‘Pay a fine at the door and go,’” she said. “We’re not talking about a traffic ticket. This is lying in a federal criminal investigation.”

Van der Zwaan’s connection to the Russia probe runs through Rick Gates, former Trump campaign chair Paul Manafort’s deputy. Mueller indicted Gates in October, along with Manafort, on charges of money laundering and illegal lobbying. Former National Security Adviser Michael Flynn and former Trump campaign adviser George Papadopoulos were both also charged with lying to investigators, and pleaded guilty. Manafort is the only figure tied to the Trump campaign and charged by Mueller who hasn’t struck a plea deal.

Van der Zwaan’s story is convoluted and involves a Ukrainian internal political dispute from a decade ago.

In the early 2010s, van der Zwaan was working in the London office of Skadden Arps, one of the world’s largest and most powerful corporate law firms. His work seemed to focus on the former Soviet Union.

During this same time period, Manafort and Gates were working for Ukrainian President Viktor Yanukovych — a Kremlin-backed leader with dubious democratic credentials.

Yanukovych was in the midst of a power struggle with another prominent Ukrainian politician, Yulia V. Tymoshenko, which he decided to solve by jailing her in the fall of 2011. Manafort and Gates’s job was to run cover for this clearly undemocratic prosecution. So they retained a team from Skadden Arps, which included van der Zwaan, to put together a “report” that conveniently concluded there was no political motive for putting her in jail.

This was a big deal in Ukraine but a relatively obscure issue for most of the rest of the world. Manafort and Gates continued their work for Yanukovych afterward, and van der Zwaan moved on to other things — most notably marrying Eva Khan, the daughter of Ukrainian-Russian billionaire German Khan, in the summer of 2017. (One of Khan’s companies is, somewhat curiously, mentioned in the infamous Steele dossier.)

But the Mueller investigation would soon deliver van der Zwaan an unhappy honeymoon. In the process of looking into Manafort and Gates’s ties to the Kremlin, Mueller’s team started investigating the Skadden Arps report. According to the indictment, FBI agents personally questioned van der Zwaan in November 2017 about his communications with Gates and an unidentified Person A.

Van der Zwaan told them that his last communication with Gates was in August 2016 and was an “innocuous text message,” and that he hadn’t spoken to Person A since 2014. This, according to the indictment, was a lie — van der Zwaan was actually secretly communicating with Gates and Person A about the Skadden report.

“In or about September 2016, he spoke with both Gates and Person A regarding the Report, and surreptitiously recorded the call,” the indictment says.

The indictment also alleges that van der Zwaan deleted an email between himself and Person A sent around the same time as those conversations — and told the FBI that he “did not know” where the email was.

Mueller’s team argued during van der Zwaan’s sentencing that the judge needed to be tough to make sure witnesses cooperate with federal prosecutors.

“We count on people to tell us the truth,” Andrew Weissman, a prosecutor on the Mueller team, told the court Tuesday.

It’s unclear when the next person charged in the Mueller probe might face sentencing, but the fact that van der Zwaan got jail time suggests they are likely to face stiff penalties.