Greg Gianforte, a Montana congressman, has lost his bid to avoid being booked, photographed and fingerprinted for assaulting Guardian reporter Ben Jacobs the day before he was elected in May.
A mugshot would likely be used against Gianforte when he runs for re-election in the 2018 midterm election.
Gianforte was never arrested and booked for the 24 May assault, which happened when Jacobs approached the candidate and asked a question, only to be thrown to the ground and punched.
Prosecutors filed the assault charge later that day and Gianforte pleaded guilty in June, shortly before being sworn in at the Capitol in Washington DC.
His attorneys argued that Gianforte should not have to be photographed and fingerprinted because he was never actually arrested.
On Friday, Judge Rick West ordered the Republican lawmaker to report to the Gallatin County detention center by 15 September to be booked for the assault charge.
Gianforte, who won his special election against Democratic candidate Rob Quist, first accused Jacobs of assaulting him, then admitted guilt and acknowledged his full responsibility for the attack. He apologized to Jacobs.
Gianforte attracted more than $116,000 in campaign donations after admitting the assault, according to reports.
He was sentenced to community service, a $385 fine and 20 hours of anger management therapy. Reports in July said that he would complete his community service as a volunteer for a company that makes custom wheelchairs for children.
Gianforte also agreed to pay $50,000 to the Committee to Protect Journalists.
Jacobs’ glasses, which were broken in the assault, were put on display in the Newseum in Washington DC.
Representatives of Gianforte and House speaker Paul Ryan did not immediately return requests for comment.
