In an unprecedented protest, nearly 500 current and former FBI agents marched to the White House Friday to demonstrate against clemency for a native American activist convicted of murder.

They don't want President Bill Clinton to pardon Leonard Peltier, who is serving two life sentences for killing two FBI agents 25 years ago.

The White House isn't saying anything about pardons but last month, a spokesperson confirmed that Clinton would be considering "executive clemency" for several people – including Peltier – before leaving office in January.

Peltier being escorted by officials
Peltier being escorted by officials

Marching in pairs, the demonstrators carried a banner Friday that read: "Never Forget."

The head of the FBI, Louis Freeh, said a pardon for Peltier would "signal disrespect" for law enforcement.

The president of the FBI Agents' Association, John Sennett, said: "There are situations in which mercy is warranted but clearly what this man has done puts him outside the reach of any presidential pardon."

FBI demonstrators
FBI demonstrators

"We are very disappointed with the FBI response," said Jennifer Harbury, a lawyer acting for Peltier. "We think it's a sad day for democracy when our armed forces march through the streets to influence a decision for mercy and justice by a civilian president."

In June, a parole examiner recommended that Peltier, 56, stay in jail until his next parole hearing in 2008.

Two agents, Ron Williams and Jack Koler, were shot to death on the Pine Ridge Indian reservation in 1975.

Peltier fled to Canada after the shooting and was later sent back to the U.S. to stand trial.

His supporters say he was wrongly convicted, that the FBI pressured witnesses to lie about his role in the shootings.

Last Monday, a former Quebec judge who led a one-day inquiry into the case found that evidence that led to Peltier's extradition from Canada was highly questionable.