A former judge in northeastern Pennsylvania pleaded guilty Friday to a racketeering conspiracy charge for his role in a kickback scheme that put juvenile defendants, many without lawyers, behind bars for sometimes minor offenses.

Michael Conahan, 58, faces up to 20 years in prison after his plea in Scranton federal court. No sentencing date was set.

Court documents do not indicate if Conahan will testify against the other former Luzerne County judge charged in the case, Mark Ciavarella Jr. Conahan's lawyer, Philip Gelso, declined to comment Friday.

Ciavarella has maintained his innocence and plans to go to trial.

Prosecutors accuse the pair of taking $2.8 million in kickbacks from two private detention facilities. Conahan, as president judge, shut down a county-owned juvenile center while Ciavarella, the juvenile court judge, filled beds at the for-profit facilities, they charged.

The indictment was part of a sweeping federal probe of corruption in Luzerne County that has so far ensnared more than two dozen people, including a school superintendent and a court administrator.

Ciavarella, 60, routinely shackled children, denied them legal counsel and removed them from their homes during brief plea hearings, juvenile advocates said. Some children were detained for possession of a drug pipe, stealing change from a car and failure to appear as a witness.

Last year, the state Supreme Court vacated the convictions of thousands of juveniles who appeared before Ciavarella from 2003 and 2008. The court concluded that he ran his courtroom with "complete disregard for the constitutional rights of the juveniles."

Both ex-judges had tried to plead guilty before. Earlier plea agreements called for 87-month terms for honest services fraud and tax evasion, but Senior U.S. District Judge Edward M. Kosik rejected the pleas, finding the pair had failed to accept responsibility for their actions.

After Kosik's rejections, Ciavarella and Conahan withdrew their pleas. A federal grand jury later returned a 48-count racketeering indictment against the pair.

Conahan, after Friday's plea, must pay a $250,000 fine and surrender his law license. Prosecutors agreed to drop money laundering, extortion and dozens of other counts, and recommend a lower sentence if he accepts responsibility.

The possible sentencing range under federal guidelines wasn't immediately clear.

Conahan spent 26 years as a judge, half as a magistrate and the rest on the county court. He served as president judge from 2002 to 2006.

Federal prosecutors first announced charges against the judges in January 2009, describing a scheme in which Conahan forced the county-owned juvenile detention center to close and reached an agreement with a for-profit company co-owned by his friend, a prominent local attorney, to send youth offenders to its new facility outside Wilkes-Barre.

Ciavarella sent youths to the PA Child Care LLC detention center and to a sister facility in western Pennsylvania while he was taking payments, prosecutor said.

According to a juvenile court judges group, 25 percent of juvenile defendants in Luzerne County received out-of-home placements from 2002 to 2006, compared with a state average of 10 percent.