A former chief of staff to ex-Rep. Bob Ney was sentenced to probation Wednesday for his role in the Jack Abramoff lobbying scandal, avoiding a stiffer sentence because he has been so helpful in prosecuting others.

Neil Volz, who pleaded guilty to conspiracy last year, tearfully apologized for his actions and noted that he is continuing to cooperate with investigators and prosecutors.

"I know the difference between right and wrong and what I did was wrong," Volz told U.S. District Judge Ellen Huvelle.

Prosecutors asked Huvelle to sentence Volz to home confinement, but she instead gave him two years of probation, 100 hours of community service and a $2,000 fine.

Volz faced a maximum of five years in prison and $250,000 in fines for his guilty plea to conspiracy.

"The government has clearly viewed you as the key to their case against Congressman Ney," Huvelle said.

Indeed, prosecutors said that had Ney chosen to go to trial rather than plead guilty to his own crimes, they would have relied on Volz's testimony to convict the former lawmaker.

The Justice Department probe of influence peddling by Abramoff and his team of lobbyists has led to convictions of a dozen people, including Ney, former White House official David Safavian and former Deputy Interior Secretary Steven Griles.

Ney, who resigned from Congress, was sentenced in January to 2 1/2 years in prison. In pleading guilty to conspiracy and making false statements, Ney acknowledged taking trips, tickets, meals and campaign donations from Abramoff in return for official actions on behalf of his clients.

Prosecutors said Volz, who went to work for Abramoff after leaving Ney's staff, provided information about trips to Scotland, New Orleans and Lake George that Ney went on, largely paid for by Abramoff.

Volz's lawyer, Timothy Broas, said Volz provided photographs and bar receipts from the Scotland trip.

Volz received abusive phone messages from Ney — which Volz provided to the government — when the congressman suspected Volz of cooperating with prosecutors. Prosecutors said the messages would have been powerful evidence of Ney's consciousness of guilty had Ney elected to go to trial.

Volz cooperated not only in the investigation of Ney, but he also testified for the government at the trial of Safavian, who was convicted by a jury of covering up his dealings with Abramoff. Safavian, who is appealing, was the Bush administration's top procurement official. Volz also provided investigators information about another ex-chief of staff to Ney, William Heaton, who pleaded guilty in the scandal.