Former Trump adviser Peter Navarro speaks at GOP convention ...

Former Trump White House adviser Peter Navarro spoke at the Republican National Convention on Wednesday, just hours after he was released from a Miami federal prison following his completion of a four-month sentence for defying a subpoena from the January 6 congressional committee.

“I got a very simple message for you. If they can come for me, if they can come for Donald Trump. Be careful. They will come for you,” he warned convention attendees in Milwaukee, where his former boss has been formally nominated as the 2024 GOP presidential candidate.

Navarro is one of two members of Trump’s circle who was convicted for failing to comply with subpoenas from the now-defunct House select committee that investigated the January 6, 2021, attack on the US Capitol. Trump adviser Steve Bannon started serving his four-month sentence earlier this month at a federal prison in Connecticut.

Navarro, who is in his 70s, worked as a law library clerk during his time in the prison camp, his prison consultant Sam Mangel told CNN.

“Everybody has to work,” Mangel said. “It gave him a chance to write.”

Mangel said Navarro was liked and respected by his fellow inmates while in the prison.

“When I went to visit him, guys were coming up to him, high-fiving him,” Mangel said.

Navarro ended his speech Wednesday at the Republican convention by calling his fiancée to join him onstage: “This is my beautiful girl. She did the time with me.”

“Now here’s the sweetest thing that’s going to come off my lips: Vote Trump-Vance ’24 for Trump 47,” he said.

Defying the subpoena

When lawmakers demanded Navarro’s participation in their probe into Trump’s election subversion schemes, they pointed to reports that he was involved in efforts to delay Congress’ certification of the 2020 presidential results, as well as to his own account in his memoir describing the election-related plots.

After just a few hours of deliberations, a federal jury found Navarro guilty last summer on two counts of contempt: for his failure to produce documents and for not showing up for an interview that the committee had demanded.

Before the trial, Navarro had sought to argue to the jury that he was acting at the direction of Trump, who had invoked executive privilege, when he refused to comply with the subpoena. The judge, however, barred him from putting forward that defense, having concluded that the former White House aide had not present sufficient evidence that Trump had formally asserted the privilege.

While Navarro was unsuccessful in an emergency appeal to delay his prison sentence, he is now appealing his conviction on the merits.

The federal correctional facility where Navarro has lived since March is one of the oldest prison camps in the country, housing fewer than 200 inmates in its aging infrastructure, with a large Puerto Rican population.

This story and headline have been updated.

CNN’s Aditi Sangal and Andrew Menezes contributed to this report.