Wide-ranging Mueller probe could end up far from where it began

The FBI's search of President Trump's one-time campaign manager Paul Manafort's home surely represents a ratcheting up of the Justice Department's Russia probe, but does that mean law enforcement soon will bring charges?

The course of high-profile public corruption cases is always unpredictable, and, as other notable criminal investigations show, once a probe is begun, the tendency is to range far beyond prosecutors' initial suspicions.

There are signs that this already is underway with special counsel Robert Mueller's investigation of allegations that the Trump presidential campaign illegally colluded with the Russian government to subvert the election. So far it is not apparent that there's any evidence to support those claims, despite numerous leaks about the probe, including the disclosures that a grand jury has been impaneled and Manafort's Northern Virginia home has been searched.

>>READ MORE: What's Robert Mueller supposed to do as special counsel?

If anything, Mueller's investigation apparently has moved in other directions, examining Trump's business dealings, Manafort's commercial ties to political figures in Ukraine, and whether their payments to Manafort comply with U.S. banking regulations.

Simply having your house searched, shocking though it may be, isn't necessarily the kiss of death. In 2003, when the FBI mounted a public corruption probe of then U.S. Sen. Robert Torricelli, they searched the New Jersey Democrat's house, subpoenaed his bank records, and put his finances and spending under a microscope.

The probe ended without criminal charges against him.

That criminal investigations, especially those that spark intense publicity and political interest, can take on a life of their own was amply illustrated by the special counsel investigation of I. Lewis "Scooter" Libby's alleged outing of CIA agent Valerie Plame in 2003.

Libby, who for a time in the 1970s was a partner at the Center City law firm of Schnader Harrison Segal & Lewis, was chief of staff to Vice President Dick Cheney. Special counsel Patrick Fitzgerald, appointed to his role by then-senior Justice Department official James Comey, charged him with lying to a federal grand jury about whether he had disclosed Plame's covert CIA identity to various media outlets.

It all began when Plame's husband, Joseph Wilson, a former ambassador and State Department official, published a column in the New York Times disputing the Bush administration's claim that Saddam Hussein had attempted to obtain yellowcake uranium, potentially to develop nuclear weapons, from the African country of Niger. Wilson came to that conclusion following a CIA-financed trip to Niger to investigate reports that Hussein was trying to buy the ore there.

Earlier, the Bush administration said it had evidence that Hussein was attempting to develop weapons of mass destruction, and that became the basis for the invasion of Iraq in March 2003.

Shortly after Wilson's column was published, Robert Novak, then a columnist for the Washington Post, published a column debunking Wilson's claim and disclosing that his wife was a "CIA operative."

War critics and political opponents of the Bush administration immediately focused on the Bush White House as the source of the leak and alleged that it had leaked Plame's name in retaliation for her husband's column. Fitzgerald soon turned his attention to Libby, who eventually was convicted of charges of lying to the grand jury and obstruction of justice. Specifically, Fitzgerald charged Libby with leaking Plame's covert status to Times reporter Judith Miller, even though it was Novak's column, not Miller's writing, that had initiated the case.

Years after the conviction, though, Miller wrote that her testimony may have been mistaken and suggested that Fitzgerald had manipulated her remarks by withholding key information about Plame's employment background.

President Bush commuted Libby's sentence before he served any jail time. And the source of the leak to Novak, whose column sparked the criminal investigation?

It wasn't Libby, but rather a State Department official named Richard Armitage, then working as a deputy to Secretary of State Colin Powell.