Larry Giberson was a sophomore studying political science when he joined the riot in Washington on Jan. 6, 2021.A 22-year-old New Jersey man was sentenced to two months in prison on Wednesday for taking part, as a Princeton University student, in the storming of the U.S. Capitol on Jan. 6, 2021, by a mob loyal to former President Donald J. Trump.The man, Larry F. Giberson Jr., pleaded guilty in July to civil disorder, a felony, after federal prosecutors charged him with that crime and several misdemeanors, according to court records. At the riot, according to a federal agent’s affidavit, Mr. Giberson cheered on others as they used weapons and pepper spray to attack the police officers guarding a tunnel and tried, unsuccessfully, to start a chant of “Drag them out!” among other actions.The misdemeanors were dismissed as part of Mr. Giberson’s plea agreement, court records show. He was also sentenced to six months of supervised release under home detention.Larry Gibersonvia FBIBefore being sentenced, Mr. Giberson, of Manahawkin, N.J., expressed remorse in court for what he called his “careless and thoughtless actions,” The Associated Press reported.“I don’t believe my defining moment was there on the Lower West Terrace,” he said, referring to the section of the Capitol he had entered, according to The A.P. “Instead, I believe my defining moment is now, standing before you.”He was sentenced by Judge Carl J. Nichols of U.S. District Court in Washington, D.C., who was appointed to the federal bench by Mr. Trump. Judge Nichols called Mr. Giberson’s actions “reprehensible” and said the two-month sentence was “something of a break,” The A.P. reported.“I do believe that his expressions of remorse, generally and then again today, are candid and truthful,” the judge said. “That’s important to me.”The maximum sentence for civil disorder is five years. Prosecutors had argued in court filings for a prison term of 11 months to be followed by three years of supervised release. The office declined to comment on Mr. Giberson’s sentence.Charles Burnham, Mr. Giberson’s lawyer, had sought a sentence that did not include prison time or supervised release. Mr. Burnham did not immediately respond to a request for comment.Mr. Giberson graduated from Princeton in May, Mr. Burnham wrote in a court filing. The Daily Princetonian, a student newspaper, reported in July that Mr. Giberson had earned a bachelor’s degree in politics and certificates in values and public life and French.It is unclear whether Princeton took any action against Mr. Giberson as a result of his arrest. A university spokesman did not respond to an email inquiry on Wednesday.Mr. Giberson is one of more than 1,100 people who have been charged with crimes stemming from the Capitol riot amid an investigation that is continuing, according to the Justice Department. More than 400 have been charged with assaulting or impeding law enforcement authorities.He was among a group of rioters who pushed against a phalanx of officers defending the Capitol at a tunnel entrance on the Lower West Terrace, according to an affidavit filed by a federal agent. With Mr. Giberson at the front of the crowd, one officer was briefly crushed between the rioters and the tunnel doors, the affidavit says.Mr. Giberson had traveled to Washington with his mother for the “Stop the Steal” rally that day after seeing Mr. Trump’s social media post urging his supporters to descend on the city to protest Congress’s imminent certification of President Biden as the winner of the 2020 election, court records show.Mr. Burnham, Mr. Giberson’s lawyer, wrote in a court filing that his client had not been motivated to come to Washington because of “membership in radical groups” or a belief in “online conspiracy theories.”Rather, Mr. Burnham wrote, Mr. Giberson had “studied the issues surrounding the 2020 election and concluded that state actors had interfered with the electoral process in unconstitutional ways.”Mr. Giberson and his mother became separated after making their way to the Capitol from the rally, court records show. After entering the tunnel and joining the push against the officers, he waved other rioters in and joined a second round of shoving against the officers, the federal agent’s affidavit says.Mr. Giberson could be seen in publicly available video footage wearing a blue “Make America Great Again” cap on his head and a Trump flag around his neck and climbing toward the tunnel entrance, the affidavit says.Federal investigators matched a photo of Mr. Giberson from the day of the riot with images posted on social media and the Princeton website, as well as with photos from his high school, the affidavit says. He was arrested in March.There is no record of his mother’s having been charged in connection with the Capitol riot. More