Top Probation Department aides granted immunity in exchange for their testimony against former commissioner John J. O’Brien

By Andrea Estes, Globe Staff

A state prosecutor said in court today that two aides to former probation commissioner John J. O’Brien have been given immunity in exchange for information about their former boss, who was indicted on state and federal charges in connection with the rigged hiring and promotion practices at the agency.

During a hearing in Suffolk Superior Court, Assistant Attorney General Peter Mullin said that both Edward P. Ryan, O’Brien’s legislative liaison, and Francis M. Wall, a former deputy commissioner, are cooperating with the US attorney’s office and the state attorney general. Both men would have first-hand knowledge of how O’Brien allegedly doled out probation jobs to politically connected candidates.

Ryan helped maintain a list of probation job applicants, noting their legislative or judicial sponsors. He also passed along the names of O’Brien’s favored candidates to supervisors screening job applicants, according to witnesses who testified before independent counsel Paul F. Ware Jr. in 2010.

Wall, who was one of O’Brien’s closest aides, was in a position to know exactly how hiring and promotional decisions were made.

The two men are among numerous former probation supervisors who are cooperating with investigators, according to lawyers involved in the case. Wall was one of the first to offer his assistance, according to someone with direct knowledge.

Lawyers said also that Ryan has testified before a federal and a state grand jury.

Today, defense lawyers for O’Brien and his co-defendant in the state charges, Scott Campbell, a top aide to former Treasurer Timothy Cahill, asked a Suffolk Superior Court judge to order prosecutors to tell them what promises were made to Ryan and Wall in exchange for their cooperation.

In the state case, scheduled for trial in September, prosecutors are alleging that O’Brien raised political donations for Cahill from probation employees so that his wife could get a job at the state Lottery, an agency under the treasurer’s control. Ryan had testified in the Ware investigation that there was no connection between a July 2005 fundraiser and the hiring of Laurie O’Brien in September of the same year.

But Campbell’s lawyer, Charles Rankin, told the judge that he had seen Ryan’s testimony before the state grand jury and it contradicts what he told Ware.

“Ryan will testify that O’Brien asked him to call the lottery and see if his wife, Laurie, could get a job there,” he said.

“He’ll say, ‘O’Brien asked me to call the lottery. I called Scott Campbell, who I’ve known for years and he said, ‘Tim Cahill wants to see about you putting on a little fundraiser,’’” Rankin said.

O’Brien, who resigned in 2010, was indicted in September on bribery and conspiracy charges in connection with the Cahill fundraiser, which brought in more than $11,000. Campbell was charged with conspiracy and campaign finance violations.

In March, O’Brien and two top aides, Elizabeth Tavares and William Burke, were indicted on federal racketeering, mail fraud, and conspiracy charges.

Andrea Estes can be reached at estes@globe.com.