After President Trump said Friday that Hillary Clinton was cleared of charges by a "rigged" system, experts said it may be possible for the Justice Department to reopen the criminal probe, although it is unlikely.

Launching a renewed investigation into Clinton's use of a private email server as secretary of state would not run afoul of the Constitution's double jeopardy clause, which bans prosecution twice for the same crime, experts say.

"The double jeopardy clause ban only applies to prosecutions, not investigations. So there is no constitutional bar to reopening the investigation," said Susan Herman, a professor at Brooklyn Law School and president of the American Civil Liberties Union.

"Jeopardy doesn't attach until a jury is sworn in a jury trial, or until the first witness is sworn in a judge trial," said Lissa Griffin, a Pace University law professor who has written about the constitutional protection.

Lack of double-jeopardy complications doesn't mean, however, that the investigation into the former Democratic presidential candidate's handling of classified information could be reopened with ease.

"The Department of Justice should be independent and free from political interference, including pressure from the president," said Jimmy Gurule, a law professor at Notre Dame University and a former assistant attorney general.

"Reopening a criminal investigation should be based on newly discovered evidence, not a political whim," said Gurule, who worked in past Republican administrations.

Trump's latest comments on the Clinton case come after Republicans on the Senate Judiciary Committee said former FBI Director James Comey began writing a statement absolving Clinton of criminal charges before the FBI conducted key interviews with her aides.

"Wow, looks like James Comey exonerated Hillary Clinton long before the investigation was over...and so much more. A rigged system!" the president tweeted.

Although Trump said from a presidential debate stage he would appoint a special prosecutor to review Clinton's conduct, the idea was quietly dropped after the election.

Gurule said Trump can't appoint a special prosecutor anyhow, though the attorney general could.

Gurule said it's conceivable Trump would commit obstruction of justice charge if he ordered an investigation reopened to damage a political opponent, especially if the matter already was reviewed by a grand jury and closed, as was the Clinton case.

"Due process prevents a prosecutor from bringing charges for political or personal reasons, but we aren't there yet," Griffin said of a theoretical renewed Clinton probe.

Griffin said it's conceivable Clinton would seek an injunction if an investigation was launched, claiming an abuse of process, and probably would claim improper motivation in a motion to dismiss if there were an indictment.

Trump fired Comey in May, with one justification his usurpation of Attorney General Loretta Lynch's power in deciding whether Clinton should face charges. Lynch had met with former President Bill Clinton privately during the investigation, creating the appearance of a conflict of interest.

Comey recommended against prosecuting Clinton, saying she was "extremely careless" with classified information but that there wasn't strong evidence of criminal intent.

The likelihood the Justice Department will reopen the Clinton case appears slim.

A spokesman declined to comment on the possibility, saying, "The Department of Justice does not generally confirm, deny, or otherwise comment on the existence of an investigation."

Even Clinton foes doubt a new criminal investigation would happen.

"It's unlikely it will be reopened for political reasons: namely, that Attorney General Sessions is on the defensive," said Larry Klayman, a conservative legal activist and longtime Clinton nemesis who served in the Reagan Justice Department.

"He's under investigation by Mueller and he's basically buried his head on any controversial issue," Klayman said, referring to former FBI Director Robert Mueller's work as special prosecutor looking into potential collusion between the Trump campaign and Russia.

Sessions was subject to intense midsummer criticism by Trump, including a July tweet that "Attorney General Jeff Sessions has taken a VERY weak position on Hillary Clinton crimes (where are E-mails & DNC server) & Intel leakers!" No action against Clinton appears to have followed that criticism.

Klayman believes Deputy Attorney General Rod Rosenstein would have to pull the trigger on a renewed probe and that he's unlikely to do so.

"In my years of fighting Bill and Hillary Clinton, the establishment leaves them alone," Klayman said. "This is a lot of smoke in terms of what the Judiciary Committee is doing. It gets them on Fox News, but when it comes to action, it's very unlikely."