SAN DIEGO -- A woman accused of deliberately driving former Chargers linebacker Steve Foley's sedan toward an off-duty policeman may not have been able to see because of the headlights on the officer's car, a defense expert testified Tuesday.

Lisa Maree Gaut, 26, is charged with assault on a peace officer and driving under the influence for allegedly trying to run down Coronado police officer Aaron Mansker, who had followed Foley on suspicion of drunken driving.

As the two cars arrived on Foley's cul-de-sac in Poway, Mansker shot Foley in the knee and hip when Foley allegedly refused orders to stop and reached into his waistband, according to prosecutors.

Forensic accident reconstructionist Joseph Awad testified that his review of the evidence showed nothing that indicated Gaut drove at Mansker just before he shot Foley, as Mansker said she did.

Awad also testified that there was "no way" Gaut could see Mansker at the top of the cul-de-sac because the high-beams of the officer's car were shining directly in her face as she tried to maneuver Foley's 1971 Oldsmobile Cutlass.

"When you are looking into these lights, everything else is not visible at all," Awad testified.

The defense expert also testified that Mansker shot Foley in the knee from behind and the side, based on the position of the football player's body when the bullet entered.

Awad, who said he was also a biomechanical expert, testified that the shot that went through Foley's hip was also fired from behind him.

Gaut testified Monday that she had no idea -- and neither did Foley, she said -- that they were being followed by an off-duty police officer after they left a downtown San Diego nightclub last Sept. 3.

The defendant testified that Foley was shot when he got out of his car on Travertine Court and walked toward Mansker.

After he was wounded, Gaut testified she told Foley that she was going to turn his custom car around to help him.

"I couldn't get it into drive to go," Gaut testified. "I couldn't understand why it wasn't going."

The defendant said she finally got the car in gear and drove straight over a curb.

She said she knew she needed to get the car in reverse, all the while being worried that "this guy's going to come over here and shoot me."

Once she backed out of a front yard, Gaut said she once again had trouble getting Foley's car into drive, continually revving the loud engine.

Mansker said he started following Foley's car around 3 a.m. when he noticed it being driven erratically through Balboa Park.

After exiting the freeway and driving onto Foley's cul-de-sac, Mansker testified that Gaut slid into the driver's seat of the athlete's car and drove straight at him, prompting him to fire at the car.

Mansker said Foley then appeared near the front of his personal, unmarked car, reached toward his waist and lifted up his shirt, prompting the officer to fire at him.

Gaut testified that she repeatedly tried to stop Foley from getting out of the car and confronting the person who was following them.

"I said, `This guy's crazy, he's going to do something,"' the defendant testified.

She said Foley told her that he didn't know who was following their car so closely.

"It's nobody. That's what he said," Gaut testified.

Gaut faces up to five years in state prison if convicted.

Closing arguments are expected to begin Wednesday afternoon.

Foley, 31, is scheduled to stand trial May 7 on two counts of driving under the influence.