SAN DIEGO -- A woman who was with former Chargers linebacker Steve Foley the night he was shot was drunk when she drove Foley's car toward an off-duty officer, a prosecutor said Thursday.

In his opening statement in the trial of Lisa Maree Gaut, prosecutor James Koerber told a jury that Gaut was guilty of assault on a police officer and driving under the influence.

Koerber said off-duty Coronado police Officer Aaron Mansker "did what he was trained to do" when he spotted an erratic driver near Balboa Park last Sept. 3 and followed Foley's car to Poway.

As they reached the cul-de-sac where Foley lived about 3:30 a.m., the football player got out of his car and walked toward Mansker, who had also exited his personal, unmarked vehicle.

Gaut, 26, slid into the driver's seat, then drove around Foley and took direct aim at Mansker, the prosecutor said.

Mansker began firing and shot out both front tires of Foley's 1971 Oldsmobile Cutlass, sending it into some bushes of a nearby home.

The officer reported the incident to a police dispatcher as a "vehicle trying to run me down."

Mansker told investigators he fired at Foley when he saw him reach into his waistband.

"(Mansker said to himself), `I'm not going home tonight. I'm not going to see my wife again,'" according to Koerber.

Mansker's first shot sent Foley to the ground, the prosecutor said.

"(Foley said), `You shot me in the knee,'" according to Koerber.

He said Mansker told investigators that he saw Foley reach into his waistband again, so he fired again.

Gaut then backed Foley's car out of the bushes and revved the engine at high speed, the prosecutor said.

Authorities who arrived on the scene yelled at Gaut to get out of the car, but she refused, Koerber said.

A sheriff's deputy noted Gaut's slurred speech and an odor of alcohol when he eventually got her out of the car, the prosecutor said.

"He noted she was under the influence of alcohol at that time," Koerber said.

Gaut's blood-alcohol level was measured at .15 percent about an hour after the shooting and would have been higher at the time she was driving Foley's car, the prosecutor said.

Defense attorney Raymond Vecchio said Gaut had met Foley a few days before the incident and they were headed to Foley's home after spending some time in San Diego and at a Gaslamp-area bar that morning.

Vecchio said Foley and Gaut didn't know Mansker was following them until they were headed north on the freeway.

The attorney said Mansker was a "relatively new officer" who twice before had followed people he thought were drinking and driving.

One motorist turned out to have diabetes and the other was just tired, Vecchio told the jury.

"This was not the first time he'd done this," Vecchio said of Mansker. "We don't concede anything he says."

In Coronado, Mansker was used to busting drunken sailors and other drunks, the attorney said.

At some point after following Foley's car, Mansker thought he was dealing with a drunken driver, Vecchio said.

After the cars exited the Pomerado Road offramp on Interstate 15, Foley stopped, got out of the car and walked back toward Mansker, who had a gun on him.

Foley told Mansker he only had a BB gun and got back in the car, both attorneys said.

When Foley got back in the driver's seat, Gaut asked him who was following them.

"It's a nobody," Foley told his passenger, according to Vecchio.

At some point, Gaut exited the car and Mansker pulled his gun out again, Vecchio said.

"Naturally, I think that would scare anybody," the attorney said.

He disputed the contention that Mansker yelled at Gaut to sit down on the curb.

Mansker had a badge on his waistband that night but never showed it, Vecchio told the jury.

Vecchio said Gaut took the wheel of Foley's car once she thought he had been shot.

"This is a car she's not familiar with in terms of how its driven," the attorney said.

He said the "reliable" evidence left at the scene will prove that Mansker was not where he said he was when he fired the shots at the car and Foley.

Vecchio called the officer "overzealous and ill-trained."

He urged the jury to acquit Gaut of charges including assault with a deadly weapon on a police officer and assault with a deadly weapon with force likely to produce great bodily injury.

Gaut is also charged with two misdemeanor counts of DUI. She faces five years in state prison if convicted of the felony charges.

Foley, 31, is charged with two counts of DUI. He is scheduled to stand trial May 7.