O’Brien declines to testify as prosecution rests in probation case

John J. O'Brien John Tlumacki/Globe Staff

Testimony in the Probation Department corruption trial concluded Friday with a retired probation chief tearfully telling jurors about his respect for former commissioner John J. O’Brien, who was once his boss.

Prosecutors threatened William Mattei with perjury charges, after the witness allegedly backtracked from previous testimony that would have reflected negatively on O’Brien.

“You’re in federal court, under oath, lying for [O’Brien] today, aren’t you,” Assistant US Attorney Karin Bell asked.

“I’m not lying,” Mattei said.

Mattei begrudgingly acknowledged that he had given a low ranking to a job candidate after interviewing him in 2005 and that the candidate was given the job anyway.

“My opinion of his work ethic,” Mattei testified, “is I found it somewhat lacking.”

But that candidate, Bernard Dow, won the job of assistant chief in Worcester District Court, after he sought the help of House Speaker Salvatore F. DiMasi, according to earlier testimony.

Mattei was the 60th and final witness to testify in the case, which began with opening statements on May 8, and his hostility toward the prosecution was typical of many of the other witnesses who took the stand.

O’Brien and two codefendants did not take the stand in their own defense, and the defense rested without calling any witnesses. Lawyers are slated to argue over the charges Monday, and jurors could hear closing arguments from both sides Tuesday. Deliberations could begin that afternoon.

Prosecutors have alleged that O’Brien, probation commissioner from 1998 to 2010, and top deputies Elizabeth Tavares and William Burke III ran the department like a criminal enterprise, by trading jobs for legislative favors.

Defense lawyers say their clients may have engaged in patronage, but did nothing illegal. Prosecutors allege the defendants committed fraud by creating a bogus hiring system to make it appear as though they were complying with hiring policies and procedures. The defendants allegedly passed over more qualified candidates for the friends of legislators.

Dow’s promotion was one of the allegedly fraudulent hires. According to testimony by Mattei and others, two other candidates scored far better in the interview process. Yet O’Brien, who had the ultimate hiring authority, chose Dow for the position.

Under questioning, Mattei acknowledged that he had told O’Brien, “Commissioner, I think you know my position and my feelings regarding Mr. Dow.”

Mattei also said that he had sued the state Trial Court system in the late 1990s after he was unfairly passed over for a job and that O’Brien had supported another candidate. Mattei was ultimately appointed to the position.

He said O’Brien later reached out to him, and he grew emotional Friday, pausing at times, as he described the meeting.

“We had a nice, professional, cordial conversation, and because of that I respect the man he is,” Mattei said.