On the same day, new video footage showing the events leading up to the controversial attack was released.
Paul Schene is charged with fourth-degree assault in the beating of 15-year-old Malika Calhoun.
Surveillance footage showed the deputy manhandling the teenage girl, throwing her down on the floor and beating her in a holding cell at SeaTac City Hall on Nov. 29, 2008.
"During the attack, Malika was so scared she wet her pants," said Gary Ernsdorff, senior deputy prosecutor.
Prosecutors added Calhoun's friend in a nearby cell heard the girl screaming, "I am not resisting!"
But defense attorney Peter Offenbecher says Schene didn't do anything wrong.
"We're not afraid of the video," he said. "We wish there was audio."
Calhoun and her friend had been taken into custody for investigation of auto theft. In the minutes leading up to the scuffle, Calhoun was confrontational, prosecutors said, but Schene egged her on, implying she was a prostitute.
"When he was wondering how much prostitutes ask (for), Malika said, 'Why don't you ask your wife?'" Ernsdorff said.
But Offenbecher said it was natural for Schene to ask whether the girls were prostitutes, since they were arrested in a high-prostitution area in the middle of the night.
Calhoun, an African-American, said Schene used a racial slur in addressing her. But prosecutor decided there wasn't enough evidence to pursue the case as a hate crime.
Offenbecher said the teen was tossing her own insults at deputies, apparently trying to provoke and antagonize them.
"She called them 'fat pigs.' She said, 'You guys are lazy, fat pigs,'" he said.
The video shows Schene ripping a necklace from the girl's neck when she was slow to remove it. The former deputy's elbow is seen jerking back with force.
But it was when Calhoun kicked a shoe at the deputies that Schene charged in. Footage shows him pushing the girl against the wall, then throwing her down and punching her.
Schene's attorney said his client, having been hit by the girl's shoe, was trying to bring the girl under control using a safe take-down method.
"He did exactly what he was trained to do under these circumstances. It does not constitute a crime of assault or any other crime," said Offenbecher.
The sheriff fired Schene last September for a number of policy violations, including the video-taped incident.
Calhoun is expected to take the stand on Tuesday.