On Thursday, Avery recanted that guilty plea, a development that could have ramifications for the landmark conviction of Philadelphia archdiocesan Msgr. William Lynn, the first U.S. church official to serve jail time for his handling of abuse claims.
The revelation came in testimony in the first week of the trial of Fr. Charles Engelhardt and former Catholic school teacher Bernard Shero, both alleged to have abused the same altar boy Avery had previously admitted to assaulting.
According to multiple reports from the courtroom, Avery took the stand and testified that he pleaded guilty only to avoid a longer sentence.
The defrocked priest has been in prison since that plea March 22, four days before he was scheduled to stand trial alongside Lynn and Fr. James Brennan.
Lynn, the former secretary for clergy for the archdiocese, has been in prison since June 22, serving a three- to six-year sentence after he was found guilty on one charge of child endangerment.
His lawyers pushed for bail and for him to be placed under house arrest while they pursued a retrial, and Thursday afternoon indicated to reporters they intend to again pursue Lynn's removal from prison.
"If there's a question about [Avery's] guilt, then there's no way you convict Lynn, because Lynn was only convicted as a derivative of Avery," Thomas Bergstrom, one of Lynn's lawyers, told the Philadelphia Inquirer.
In September, Lynn's defense team accused the prosecuting district attorney's office of withholding evidence of Avery passing a polygraph test in which he denied assaulting his accuser.
The conviction of Lynn for child endangerment was largely tied to the Avery confession.
The monsignor was acquitted of one child endangerment charge and one conspiracy charge, both related to Brennan, on whose case the jury declared itself hung after members were unable to reach consensus on charges of abuse of a 14-year-old boy.
Both Engelhardt and Shero were set for trial with Lynn and Brennan in March, but won a bid for their case to be separated from Lynn and Brennan on the basis that neither was directly affiliated with the archdiocese.
Engelhardt is a priest of the Oblates of St. Francis de Sales.
Their cases, along with Avery's, are tied to "Billy Doe," the 24-year-old man who has accused Engelhardt, Shero and Avery.
His accusations of multiple sexual assaults were recounted in detail in the Philadelphia district attorney's 2011 grand jury report.
"Billy Doe" took the stand Tuesday, testifying for more than two hours.