“I plead guilty, your honour,” Sandford told US District Judge James Mahan when asked for his plea to being an illegal alien in possession of a firearm and disrupting an official function.

“I tried to take a gun from a policeman to shoot someone with, and I’m pleading guilty,” he said.

Sandford didn’t get the gun before he was arrested, and no shots were fired.

The judge said he was satisfied that Sandford was fit to enter the plea, even though the defendant said he had taken the anti-psychotic medication risperidone.

Sentencing was set for December 13 and Sandford was ordered to remain in federal custody.

Under terms of his plea agreement, Sandford could face between 18 and 27 months in a US prison for his two felony convictions. He will get credit for time served, accepting responsibility for the crime and avoiding trial, which had been set to start October 3. He won’t be able to appeal.

Sandford could have faced up to 20 years in prison if convicted of both charges at a trial, and up to 30 years on the three charges he initially faced.

One charge of being an illegal alien knowingly in possession of a firearm will be dropped, prosecutor Nicholas Dickinson said.

Sandford is “almost certain” to be deported and banned from returning to the US, according to the plea agreement in which he acknowledges he overstayed his tourist visa and was in the US illegally for almost 10 months at the time of his arrest.

Saimo Chahal, a British lawyer representing Sandford’s family, said earlier that a psychiatrist she enlisted to review the case determined that Sandford was delusional at the time of the attempted attack. Sandford also suffers seizures, obsession-compulsion, anxiety and autism spectrum disorders, Chahal said.

“Michael was not in control at the time of the events and needs help,” the attorney said in an email before the hearing.