WASHINGTON (AP) – The Justice Department is putting a former junior associate at Jack Abramoff's firm on trial for a third time, making the recalcitrant and little-known lobbyist the most prosecuted figure in the influence-peddling scandal.

Kevin Ring is one of only three of the 21 defendants in the case that exposed back-room dealmaking in Washington who did not reach a plea deal. His case shows the risks that come with such defiance in the face of determined prosecutors. The Justice Department has responded by using the full force of its vast resources to see him convicted of multiple felonies that leave him facing years in prison while others accused of similar conduct got probation and fines.

Justice Department spokeswoman Laura Sweeney declined to discuss the ongoing legal battle Ring is facing, but she rejected Ring attorney Richard Hibey's claim that the case “has elements of undeniable vindictiveness.”

“We've moved forward with this case based on the facts and the law, nothing else,” Sweeney said.

In the entire scheme of the lobbying scandal, the 40-year-old Ring was a relatively minor player. The leader, Abramoff, and his business partner Michael Scanlon were convicted of conspiring to bilk their Indian casino clients out of $85 million in fees. Abramoff also admitted bribing public officials and tax evasion, but he cooperated with investigators and was sentenced to four years in prison. Scanlon also cooperated and was sentenced to 20 months.

Two high-ranking public officials caught up in the scandal – former Rep. Bob Ney, R-Ohio, and former Deputy Interior Secretary Steven Griles – also cooperated with prosecutors, were sentenced to prison and have served their time. Several other Abramoff subordinates and more junior staffers from the Bush administration and Congress have pleaded guilty for trading meals and event tickets for official favors, but none have gotten prison time. A few still are awaiting sentencing.

Ring's charges fit the pattern of those who have gotten the lighter sentences even though he's facing significant time. He was accused of taking government officials out to dinner and giving them tickets to sporting events and concerts so they would be open to doing him favors.

Rewarding those who cooperate is a longtime practice in criminal law. Rebecca Lonergan, a former prosecutor who teaches as the University of Southern California, said cooperation can be especially valuable in complicated white-collar investigations for collecting evidence against higher targets.

“The bigger and more complex the crime is, the more interested the government is in cooperation,” Lonergan said.

In a letter to Attorney General Eric Holder five months ago requesting dismissal of the case, Hibey said Ring cooperated with investigators in a dozen interviews lasting roughly 65 hours. Hibey accused prosecutors of becoming intent on charging Ring when he wouldn't implicate his former boss and friend, then-Rep. John Doolittle, R-Calif., a target of their investigation who was named as a co-conspirator in Ring's case but never charged.

Hibey wrote that when it became clear that Ring would be indicted, he repeatedly asked prosecutors if his client could turn himself in. But instead, he said, in September 2008 a team of armed FBI agents raided Ring's home in Kensington, Md., at 7 a.m. and took him away in handcuffs and shackles in front of his daughters, then 3 and 5. Hibey called that particularly vindictive since later that afternoon prosecutors said they had no objection to Ring being released pending trial.

Ring was indicted with 10 felony counts, including conspiracy, payment of an illegal gratuity to a government official, honest services wire fraud and obstruction of justice.

Ring went on trial for eight bribery-related counts in fall 2009. He argued that his wining and dining of Washington insiders was standard practice for a lobbyist and not illegal. Much of the evidence against him came from his own emails, where he would ask for things like special-interest spending provisions for his clients while offering tickets. “You are going to eat free off of our clients,” he wrote to a congressman's chief of staff who was particularly helpful.

After a month of testimony and deliberations, the jurors were unable to agree whether he was guilty or not, and U.S. District Judge Ellen Segal Huvelle declared a mistrial.

Prosecutors decided to try again and won. In November 2010, a second jury convicted Ring on five counts and found him not guilty on three others. His charges carry a possible sentence of up to life in prison, although it's unlikely the judge would give a first-time offender that much time. And he has paid other steep costs already – his marriage has ended and he continues to amass millions in legal fees, Hibey explained in his letter to Holder.

The Justice Department now plans to try Ring on the two remaining charges – that he obstructed justice by lying to a lawyer hired by his lobbying firm to investigate the scandal and who later turned evidence over to the FBI. Huvelle on Tuesday set a trial for May 24, but this time she is planning to issue the verdict without a jury. Then she plans to sentence Ring on any counts for which he stands convicted.