Washington (AFP) - Filing criminal charges against Donald Trump would be a long and complex process ultimately requiring US Attorney General Merrick Garland to weigh the enormous legal and political implications of placing a former president on trial.

The House committee that investigated the January 6, 2021 storming of the US Capitol by Trump supporters recommended Monday that Trump be prosecuted for his efforts to overturn the 2020 election won by Joe Biden.

The bipartisan panel voted unanimously to refer Trump to the Justice Department for insurrection, obstruction of an official proceeding, conspiracy to defraud the United States and making false statements.

Trump, who has announced plans to run for the White House again in 2024, is already the target of a probe by a special counsel appointed by Garland last month to oversee the various investigations into the former president.

One probe is focused on Trump's maneuvers surrounding the 2020 election and the other is an investigation into a cache of classified government documents seized in an FBI raid on his Mar-a-Lago residence in Florida in August.

Special counsel Jack Smith will decide whether Trump, who has denounced the probes as a "witch hunt" by vengeful Democrats, should be indicted, but it will be Garland, as the nation's top law enforcement official, who would have to sign off on any charges.

Legal analysts said it is not a foregone conclusion that the 76-year-old Trump will ever face the inside of a courtroom.

"We have not prosecuted a former president," said John Dean, who served as White House legal counsel to president Richard Nixon, who resigned and was pardoned by Gerald Ford before he could face charges connected with the Watergate scandal.

"And there are all kinds of political fallout from that," Dean told CNN. "There are practical fallouts from that and there are legal fallouts from it."

"So it's a very complex and very interesting and very historic event."

'No one' above the law

While Dean was cautious, Bennie Thompson, a Mississippi lawmaker who chaired the House committee, said he was "convinced" the Justice Department will charge Trump.

"No one, including a former president, is above the law," Thompson said.

Playing a pivotal role will be the 70-year-old Garland, who was denied a lifetime seat on the Supreme Court by Senate Republicans only to be named attorney general by Biden, a Democrat.

Throughout his career which includes years as a federal court judge, Garland has scrupulously avoided becoming enmeshed in politics, and an indictment of Trump would likely ratchet up tensions even further in a country already bitterly divided along Democratic and Republican lines.

Garland's decision to appoint an independent prosecutor to oversee the Trump probe was seen in Washington as a bid to rebuff charges that it is politically motivated.

Garland said a special counsel was in the public interest because both the Republican Trump and Democrat Biden have stated their intention to run in 2024, although only Trump has officially declared for now.

A graduate of Harvard Law School, the professorial and soft-spoken Garland is no stranger to high-profile investigations.

As a federal prosecutor, he notably led the probe into the 1995 Oklahoma City bombing by far-right extremists that left 168 people dead. He also prosecuted Ted Kaczynski, the "Unabomber."

Garland went on to serve as chief judge on the US Court of Appeals for the District of Columbia and was nominated to the Supreme Court by president Barack Obama in March 2016.

But the Republican majority in the Senate declined to hold a vote on his nomination and it was the next president -- Donald Trump -- who filled the vacant seat.