WASHINGTON (AP) — When Sen. Richard Burr stood and said “guilty” there were hushed gasps in the Senate chamber. But the North Carolina Republican’s vote to convict former President Donald Trump should not have come as a shock.

In a way, he had been telegraphing his willingness to hold Trump accountable for several years.

Months before Trump would begin falsely claiming that the November election had been stolen from him, the Senate Intelligence Committee led by Burr warned that sitting public officials should use the “absolute greatest amount of restraint and caution if they are considering publicly calling the validity of an upcoming election into question.” Such grave allegations, the committee said in February 2020, can have “significant” consequences for national security.

Explaining his vote to convict Trump of inciting an insurrection at the Capitol on Jan. 6, Burr returned to that theme. He said Trump “promoted unfounded conspiracy theories to cast doubt on the integrity of a free and fair election.”

There was no widespread fraud in the election, as Trump claimed falsely over several months and again to his supporters just before the riot, a fact confirmed by election officials across the country and even Trump's then-attorney general, William Barr.

When the Capitol was attacked, Burr said in the statement, Trump “used his office to first inflame the situation instead of immediately calling for an end to the assault.”

For Burr, it was an emphatic statement after years of careful commentary about Trump, much of it made as he investigated Trump's ties to Russia. The “guilty” vote placed him among a group of seven Republicans in the Senate -- and 10 Republicans in the House -- who made Trump’s second impeachment the most bipartisan in history.

With Burr retiring at the end of his term in 2022, it’s a vote that could end up defining his career.

It also came with price.

The North Carolina Republican Party unanimously voted to censure Burr in the days after the Feb. 13 vote as Republicans in the state and across the country made clear their continued loyalty to Trump.

“Wrong vote, Sen. Burr,” tweeted former Republican Rep. Mark Walker, who has already declared his Senate candidacy. “I am running to replace Richard Burr because North Carolina needs a true conservative champion as their next senator.”

Burr declined to be interviewed for this story. But many of his GOP colleagues praised him after the vote.

North Carolina Sen. Thom Tillis, a Republican who voted to acquit Trump, said after the state censure vote that Burr is a “great friend and a great senator” who had voted his conscience. Nebraska Sen. Ben Sasse, one of the seven Republicans who voted to convict and a member of the Intelligence Committee, said Burr "is a leader, not a motormouth" who distinguished himself with bipartisan work on the committee.

“Richard doesn’t shy away from making tough calls because he does his homework and knows the facts — he doesn’t waste time sticking his finger in the wind,” Sasse said.

A quirky, quiet politician known for his dry sense of humor, his distaste for wearing socks and for driving a 1970s-era convertible Volkswagen plastered with bumper stickers, Burr has served in Congress for almost three decades. A former Wake Forest football player and lawn equipment salesman, he was elected to the House during the Republican wave of 1994 and became close friends with Rep. John Boehner, R-Ohio, before Boehner ascended to speaker.

First elected to the Senate in 2004, Burr said after his reelection in 2016 that his third term would be his last —- a preemptive retirement from politics that proved consequential.

After Trump’s election, Senate Majority Leader Mitch McConnell, R-Ky., wrestled with how to respond to allegations of Russia’s interference in the presidential election that Trump had just won. With Burr not seeking another term, he was an ideal candidate to lead the politically explosive investigation.

Empowered as committee chairman, Burr gradually became a quiet check on Trump’s powers during the three-year investigation. He worked closely with the top Democrat on the committee, Virginia Sen. Mark Warner, as they sifted through highly classified information, some of it about Trump and his associates.

Burr kept up the partnership until the end, even as Republicans turned sharply against the Russia investigation and followed Trump’s lead in labeling it all a “hoax.”

Warner said in an interview that he thinks that one of the main things that guided Burr was to ensure that intelligence agencies got “the respect they deserve.” That meant pushing back on Trump, who criticized the agencies for investigating Russia and suggested they had conspired against him by undermining the 2016 election. Burr endorsed the agencies’ 2017 conclusion that Russia had interfered in the election and had favored Trump, even as the former president declined to do so.

Burr has “shown time and again he’s going to do what he thinks is right,” Warner said.

Warner’s counterpart across the Capitol, House Intelligence Committee Chairman Adam Schiff, D-Calif., said Burr worked with Democrats in good faith and was committed to ensuring that the agencies “could do their jobs without fear of politicization.”

But Burr was also politically careful.

As the committee revealed Russia’s hacking and misinformation efforts around the 2016 election, and warned of future attacks, Burr did so mostly without directly criticizing Trump. Repeatedly, Burr said he saw no evidence of coordination with Russia, keeping him in the good graces of his fellow Republicans and the White House.

But unlike others investigating election interference, Burr rarely talked about his work. He also said he would stop visiting the White House while the investigation was underway.

In a rare interview with The Associated Press in the summer of 2018, Burr said the Russia investigation had been “frustrating as hell.” But he also said that the integrity of the inquiry — and its importance to the Senate — was something worth protecting. “Nothing in this town stays classified or secret forever,” Burr said, adding that people would scrutinize his efforts in the future.

But as the investigation dragged on, patience wore thin among his GOP colleagues. More than two years into the investigation, in May 2019, Burr subpoenaed Donald Trump Jr., the president’s son who had met with a Russian lawyer during the campaign. The backlash from his own party was swift.

Burr stood by the decision. He explained his rationale in a private GOP lunch to his skeptical colleagues, winning the support of McConnell.

Exactly a year later, as the Russia investigation was wrapping up, Burr’s time leading the committee came to an abrupt end.

Federal agents arrived at Burr’s Washington-area home and seized his cellphone. The Justice Department was investigating whether he had exploited advance information when he unloaded as much as $1.7 million in stocks in the days before the coronavirus outbreak caused markets to plummet. Burr denied trading on private information but stepped aside from his role on the committee amid the uproar.

He wasn’t cleared until almost a year later — on Jan. 19, Trump’s last full day in office. A department spokesman confirmed it would not bring charges against Burr but declined further comment.

Doug Heye, a Republican strategist and a former Burr aide who has known him for more than 20 years, said Burr never wavered even as the political landscape in Washington changed over the past five years. He said it would have been politically easier for Burr to run a Russia investigation like the one in the House, which was highly partisan.

“I didn’t know he was going to convict, but I wasn’t terribly surprised,” Heye said.

As the impeachment process unfolded in January, Burr said very little. Unlike some of his colleagues who were agonizing publicly over their votes, he declined to talk to reporters around the Capitol. He sided with most Republicans in a vote to dismiss the trial, creating an expectation he’d also vote to acquit.

So when Burr stood up to vote for Trump's conviction, many in the chamber wondered if there would be other surprises. Could there be enough Republican “guilty” votes to make Trump the first president even convicted at an impeachment trial? Was Burr a bellwether?

He was not. The vote was 57-43, 10 votes short of the needed two-thirds majority. In the end, seven Republicans had voted to convict — but only Burr’s came with no warning.

“I do not make this decision lightly,” Burr said in a statement after the vote, “but I believe it is necessary.”