WASHINGTON — Roger Stone obstructed a congressional investigation into Russia's interference in the 2016 election — and he did so in order to help and protect his longtime ally, President Donald Trump, Assistant U.S. Attorney Jonathan Kravis told jurors Wednesday.

"The evidence showed that Stone not only tried, but succeeded in impeding the committee’s investigation," Kravis said during closing arguments of Stone's criminal trial on allegations he lied to Congress. "A person who is acting in good faith would not say and do the things that Roger Stone said and did ... It shows you exactly what was in his head all along: to obstruct the committee’s investigation."

Stone's defense attorney, Bruce Rogow, countered by saying the longtime operative had no reason to lie to Congress to protect Trump and the campaign. Doing so was a "nonissue," Rogow said. When Stone testified before Congress, the campaign was long over and Trump was already president. 

"Why would Stone lie, why would he make stuff up?" Rogow said, adding that Stone volunteered to testify publicly. "There is no purpose, there is no reason, there is no motive."

Stone, a fixture in GOP politics known for his flamboyance and combativeness, is accused of lying to the House Intelligence Committee in 2017 about his back-channel efforts to push for the release of damaging emails about the Democratic National Committee during the 2016 presidential campaign. He's also accused of falsely denying he talked to the Trump campaign about his efforts and of forcing a witness to also lie to Congress.

The committee, at that time, was investigating Russia's interference in the 2016 election and possible ties to the Trump campaign. 

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The 67-year-old longtime operative is among the most prominent Trump allies to be charged as part of former special counsel Robert Mueller's investigation into Russia's meddling in the last election. The trial nears its conclusion as an impeachment inquiry fueled by allegations that Trump sought to have another country interfere in the next election gains steam. 

The charges against Stone present the first clear picture from prosecutors about how the Trump campaign sought to learn about WikiLeaks' plans to publish emails that would hurt Democratic rival Hillary Clinton in 2016. Testimonies from government witnesses over the past week portrays the Trump campaign as an eager beneficiary of WikiLeaks' emails dumps, and Stone as the conduit who had boasted about his connections to WikiLeaks. 

Stone, who has maintained his innocence, faces seven charges: one count of obstruction of an official proceeding, five counts of false statements and one count of witness tampering. Wearing a dark gray suit, Stone appeared at his trial accompanied by his wife and daughter. 

This story will be updated.