After less than four days of testimony, the prosecution rested in Winona Ryder's shoplifting trial Thursday in Beverly Hills Superior Court, with a security guard denying that she called the actress a female dog or pressed her for the phone numbers of Bono and Keanu Reeves, PEOPLE reports.

Colleen Rainey, a Saks security guard who had earlier testified that she saw Ryder snipping security tags off merchandise in a dressing room, was grilled in a tough cross-examination. Ryder's attorney, Mark Geragos, asked whether Rainey tried to sell the Ryder story to the tabloids. Rainey denied it. She also denied going through Ryder's Filofax looking for celebrity phone numbers, denied throwing anything at Ryder and denied seeing anybody lift up Ryder's shirt to expose her breasts.

"Did you call her a 'bitch' at one point?" Geragos asked.

"Absolutely not!" said Rainey.

The "Girl, Interrupted" star, 31, faces up to three years behind bars if convicted on charges of grand theft, second-degree burglary and vandalism for allegedly walking out of the Beverly Hills Saks with nearly $6,000 in unpaid merchandise last Dec. 12. She has pleaded not guilty to the charges.

The final witness of the trial was Beverly Hills Police Detective Mark Parker, who at the time of the alleged shopping incident was a patrolman who arrested Ryder and confiscated the orange-handled scissors that Rainey said Ryder used to snip off the security tags. Under cross-examination, Parker was a little fuzzy on whether Ryder handed the scissors over or whether Rainey reached into Ryder's jacket pocket and took them.

Parker was also the latest witness to recall overhearing Ryder tell security guards after she was apprehended that she was doing research for an upcoming movie. "She was explaining that she was getting into character for a role that was upcoming playing a kleptomaniac," he said. "She wanted to know what it felt like."

At day's end, Judge Elden Fox said the defense would begin its case on Friday afternoon. Geragos refused to say whether Ryder would testify. The judge said the case should go to the jury by Monday.