NORTHAMPTON - The former acting chief probation officer at Hampshire Superior Court was arrested Wednesday on obstruction-of-justice charges in connection with an ongoing federal probe into corrupt hiring practices in the state's probation department.

Christopher J. Hoffman, 39, of 119 Main St., Hatfield, faces one charge each of intimidating and harassing a witness in an attempt to obstruct a federal investigation, according to U.S. District Attorney Carmen M. Ortiz.

Hoffman made an initial appearance in U.S. District Court in Worcester Wednesday morning following his arrest, where he was released on several conditions requested by the prosecution, said Christina Sterling, a spokeswoman for the U.S. district attorney's office in Boston.

Among those conditions are orders to have no contact with state Rep. Thomas Petrolati, D-Ludlow, or members of his family, or with William H. Burke III, former deputy probation commissioner, or members of his family. He also must stay away from any current or former members of the state probation department.

He has yet to enter a plea, Sterling said.

Hoffman is the first person to face federal charges in relation to the probation department investigation. Former probation commissioner John J. O'Brien was earlier indicted by a state grand jury on charges he exchanged campaign contributions with former state treasurer Timothy Cahill for a job for O'Brien's wife.

The criminal complaint alleges that on Oct. 18 and 19, Hoffman made threatening and intimidating remarks to Maureen Adams, a probation officer under his supervision in Northampton. Adams was scheduled to be interviewed by the FBI in connection with the federal investigation into alleged fraudulent hiring practices at the Office of the Commissioner of Probation.

Federal prosecutors say Hoffman knew Adams was scheduled to be interviewed by the FBI and allegedly told her: "I'm going to tell everyone that you are a rat."

Hoffman is also alleged to have made misleading statements regarding his relationship with Burke, also of Hatfield. Federal prosecutors allege Hoffman's remarks to Adams were "intended to be intimidating and influence her statements to the FBI."

Hoffman could not immediately be reached for comment Wednesday afternoon. His attorney, Vincent A. Bongiorni of Springfield, told The Republican of Springfield that Hoffman maintains his innocence.

Hoffman was placed on paid administrative leave in late October, and continued to receive his annual salary of $73,170. He had been appointed acting chief probation officer on Dec. 14, 2009, when the former chief, Paul Kingston, retired. A permanent chief has not been named due to a hiring freeze across all state courts.

If convicted on the charges, Hoffman faces up to 20 years in prison and fines of up to $250,000.

Earlier action

Earlier this year, federal prosecutors opened an investigation into allegations of corruption in hiring and promotion practices within the state's probation system.

Ortiz, the U.S. attorney, had notified probation managers to preserve all agency documents, emails, cellphone messages and computer files while a grand jury investigates potential violations of federal law.

State Attorney General Martha Coakley's office is conducting its own parallel probe, and earlier brought the corruption charges against O'Brien, who resigned in the wake of the scandal last year.

Both probes followed investigative articles by The Boston Globe and a scathing report issued in November 2010 by Paul F. Ware Jr., an independent lawyer assigned to review the issue by the state's Supreme Judicial Court.

Ware alleged patronage played a role in hiring and promotions within the department and that probation employees had a "pay for play" arrangement with elected officials, particularly Petrolati, who represents Ludlow and parts of Chicopee, Springfield and Belchertown.

State election records indicate Hoffman contributed $500 to Petrolati's political campaigns, donating $100 each year from 2006 to 2010. Hoffman was not mentioned by name in Ware's report, although two other local men were, including Burke, the retired deputy commissioner of probation who was in charge of hiring in western Massachusetts. Burke is among several high-ranking officials considered potential targets in the federal and state investigations.

According to the Ware report, Burke admitted giving special treatment to job applicants put forward by elected officials, including Petrolati. Burke said Petrolati would call him with names of favored candidates for positions in western Massachusetts.

Ware's report also singled out Robert Ryan, chief probation officer at Eastern Hampshire District Court in Belchertown, whose wife, Colleen Ryan, worked as an aide to Petrolati.

A former federal probation officer, Ryan was "extremely well qualified" for the Belchertown post and likely would have been hired without support from politicians, Ware found.

Dan Crowley can be reached at dcrowley@gazettenet.com.