Julian Assange has been found guilty of failing to surrender to authorities in Britain. Following his arrest Thursday morning at the Ecuadorean Embassy in London, the WikiLeaks founder appeared before Westminster Magistrates Court later in the day to answer the charge he was officially arrested for, dating from a 2012 warrant.

Assange, who pleaded not guilty to breaching bail, could face up to 12 months in a British jail following the guilty verdict. He did not give evidence at the hearing.

The British judge hearing the case called Assange’s behavior that “of a narcissist who cannot get beyond his own selfish interest,” saying his assertion that he had not had a fair hearing was “laughable.” Assange was then sent to Southwark Crown Court for sentencing.

Assange was arrested Thursday morning by Scotland Yard officers, who were invited into the embassy by the Ecuadorean ambassador following the South American government’s decision to withdraw diplomatic asylum for Assange. He had taken refuge in the embassy in June 2012 to avoid extradition to Sweden on allegations of sexual assault. Although that case has since been dropped, a British arrest warrant remained open for the WikiLeaks founder “for failing to surrender” to authorities.

His arrest opens up the possibility of extradition to the U.S. on federal charges of conspiracy to commit computer intrusion, which the Trump administration said it would pursue against Assange after his arrest. Assange’s lawyer, Jennifer Robinson, said she would fight the extradition request, saying it set “a dangerous precedent.”

“We’ve today received a warrant and a provisional extradition request from the United States alleging that he has conspired with Chelsea Manning in relation to the materials published by WikiLeaks in 2010,” said Robinson, speaking outside the British court. “This sets a dangerous precedent for all media organizations and journalists in Europe and elsewhere around the world. This precedent means that any journalist can be extradited for prosecution in the United States for having published truthful information about the United States.”

Standing with Robinson, WikiLeaks editor-in-chief Kristinn Hrafnsson said it was “a dark day for journalism.”

The British government must now decide whether to grant the extradition request. If convicted, Assange could face up to five years in U.S. prison.

Assange has long feared extradition to the U.S. to face allegations of leaking embarrassing top-secret U.S. documents. Some in the U.S. have called for Assange to face the death penalty. In April 2017, former U.S. Atty. Gen. Jeff Sessions called his arrest a “priority.”

Announcing his decision to end Assange’s political asylum, Ecuadorean President Lenin Moreno said he had “requested Great Britain to guarantee that Mr. Assange would not be extradited to a country where he could face torture or the death penalty.” He said the British government had confirmed this in writing.

Assange could also face renewed pressure to appear in Sweden. Elisabeth Massi Fritz, the lawyer for the Swedish woman whose case against Assange was the initial cause of his fleeing inside the embassy, issued a statement to Britain’s Guardian newspaper saying she was going to do everything possible “to get the Swedish police investigation reopened so that Assange can be extradited to Sweden and prosecuted  for rape.”

The activist’s friend Pamela Anderson, a frequent visitor during his time at the Ecuadorean Embassy, attacked the British government on Twitter for its actions, calling the U.K. “America’s bitch.”