Singer said Duhaney, who will be a key witness against Williams, cut a deal with the government in hopes of a lesser sentence. Singer said that's Duhaney's "whole motive in this case."
Dimson and Duhaney served prison terms at the same time at a federal penitentiary in Montgomery, Ala. Duhaney served nearly five years of a seven-year sentence on a cocaine charge before being released in 2005; Dimson served less than one year of a two-year sentence on a bank fraud charge before his release in 2004.
Williams does not have a criminal record, another attorney who previously represented her has said.
Asked by a government lawyer Monday why he was testifying, Duhaney said, "I'm hoping for the truth to get out."
FBI agent Chad Hunt testified Monday that a man identifying himself as "Dirk" sent a letter in early May 2006 to Antonio J. Lucio, senior vice president of Insights and Innovation for PepsiCo.
In the letter, "Dirk," who the FBI has identified as Dimson, said he had detailed information about Coca-Cola's marketing plans for the next four years and was willing to sell it to the "highest bidder." He said the information could help Pepsi win the "cola wars."
Specifically, "Dirk" said he had information on Coca-Cola's plans for marketing its new coffee-infused drink, Coca-Cola Blak.
The lightly carbonated, mid-calorie beverage, is designed to appeal to adult consumers. The drink includes real coffee and has a coffee-like froth when poured, Coke has said.
"What if you knew the markets they were going to move into and out of ... and beat them to the punch," "Dirk" said in the letter to Pepsi, which Hunt read to the jury.
Hunt said the letter left a telephone number, which the FBI later tapped.
Singer said her client was messing up at work and decided to make copies of every document she dealt with and take them home to protect herself in case her boss accused her of not doing her job.
Singer said Williams never intended to give the materials to Dimson and Duhaney, or anyone else.
Jury selection began last Tuesday. The trial is expected to last another week or two.