"Did you love Mr. Tannenbaum?" Duffy thundered accusingly at Levine.
"At one time, yes, sir," Levine said.
"And yet the man who had been so good to you for 20 years -- you stole from his children, didn't you?" Duffy said.
"Yes, sir," Levine said meekly.
Duffy, a former federal prosecutor, had promised a highly aggressive cross examination and delivered on that promise. He painted Levine as a career crook who had not held a 9-to-5 job since 1976 and lied to his wife and kids.
Levine acknowledged he had engaged in marathon drug sessions in a suburban hotel known as the Purple Hotel but insisted he never held such session on Saturdays because those were days he spent with family.
With that, Duffy pulled out a credit card bill showing that Levine had charged $761 to the Purple Hotel on Saturday, Nov. 2, 2002.
Levine said the room might not have been used on the day that the credit card company recorded the transaction but Duffy pushed ahead.
"You cannot, Sir, say with any certainty that you did not have a room at the hotel on November 2nd, 2002, can you?" Duffy asked.
"No, Sir," Levine said.
Rezko, 52, is charged with scheming with Levine to squeeze kickbacks out of money management firms seeking to invest assets of the $40 million state fund that pays the pensions of thousands of retired school teachers.
He also is charged with scheming with Levine to split a $1 million bribe from a contractor who wanted to build a hospital in Crystal Lake.
Prosecutors say Rezko, who raised huge sums for Rod Blagojevich's campaign, used the influence he gained to become the power behind boards. Rezko insists he took part in no such schemes. Gov. Blagojevich has not been charged with any crimes.
But Levine has pleaded guilty and taken the stand for the government in hopes of a lenient 5 1/2-year prison sentence.
Duffy has insisted for months that Levine was so severely crippled mentally by decades of downing cocaine, ecstasy, crystal methamphetamines and other illegal drugs that his testimony is completely unreliable.
Levine stumbled over numerous dates under Duffy's questioning.
At one point, Duffy got Levine to testify he remembered sitting on the witness stand and reading a copy of his plea agreement after it became an exhibit at the trial.
Duffy then pointed to the government's exhibit cart and asked prosecutors to produce a copy of the plea agreement.
"We will stipulate that there is no such exhibit," federal prosecutor Christopher S. Niewoehner said with admirable dignity and a straight face.
Besides hammering Levine for his life of crime, Duffy also sought to show that the witness would lie about Rezko if it suited his purpose. The jury already has heard that Levine could go to federal prison for the rest of his life if he failed to cooperate with the government.
Duffy showed no mercy in pointing out Levine's long list of failings.
"If I describe you as a liar, is that a correct statement?" he asked.
"Yes, Sir," Levine said.
"So I would be correct if I called you a thief?" Duffy asked.
"Yes, Sir," Levine said.
"Can you argue with me -- you are a con man, are you not?" Duffy asked.
"Yes, Sir," Levine said.
"But you wouldn't try to pull a con on this jury, would you, Mr. Levine?" Duffy asked.
"No, Sir, I would not," Levine said.
The Associated Press contributed to this report.