Allison Coss, 24, testified in her own defense in federal court, where she and co-defendant Scott Sippola, 31, are accused of demanding money from Stamos and threatening to sell photos to magazines of him with strippers and cocaine.
Defense attorneys argued that it wasn't a crime to make a business deal, but prosecutors said it was a ruse and the photos didn't exist.
Coss admitted Wednesday that she lied in e-mails to Stamos to try to get him to pay. But she said a picture of him with cocaine did exist at least a week before the FBI raided a home she shared with Sippola last December.
Police and FBI agents testified earlier Wednesday that no pictures were destroyed after the search.
Coss took the stand shortly after the government wrapped up its case Wednesday morning, a day after Stamos testified that he neither did cocaine nor acted inappropriately when he met Coss in 2004. Jurors could begin deliberating Thursday.
The 46-year-old "Full House" and "ER" star, who is preparing to join the Fox show "Glee," watched the trial from the front row on Wednesday. A day earlier, he told jurors how he met Coss in Orlando, Florida, while "heartbroken" and separated from wife and supermodel Rebecca Romijn in 2004.
Stamos denied defense lawyer Sarah Henderson's accusation that he stripped and sat in a hot tub with the scantily clad Coss, who was 17 at the time.
More than a dozen officers, including FBI agents, searched the Coss-Sippola home last December. Coss and Sippola were arrested after undercover FBI agents fooled them into believing that a Stamos representative would fly to Michigan with a bag of cash.
The trial has been front-page news in Marquette, a city of 20,000 on the shore of Lake Superior. The courtroom has been more than half-full with the curious, and Stamos has mingled with the public outside and signed autographs.
AP ljm
