The wife of a police officer on trial for the off-duty shooting of an Oceanside woman after a road rage incident testified today she was terrified when the woman followed them and drove at their car.

Jacquellyn White told a Vista jury that she thought whoever was in the car that followed theirs into a parking lot on March 15, 2008, was going to kill her husband Frank as he prepared to exit his vehicle.

"It was very terrifying," she said. "It was very, very, scary and terrifying. They wouldn't leave us alone."

The witness will wrap up her testimony tomorrow.

Her 29-year-old husband is charged with felony gross negligent discharge of a firearm and a misdemeanor count of displaying a firearm in an angry or threatening manner in connection with the run-in with Rachel Silva.

White -- who is on administrative leave without pay from the San Diego Police Department -- faces up to nine years in prison if convicted.

He testified last week that Silva looked "upset and crazy" when he encountered her in the parking lot in Oceanside.

White testified that he had no idea why Silva was tailgating him. He said the motorist didn't respond when he pointed his gun at her.

The officer said he was scared that the person following him might have been somebody he had arrested in the past.

Holding back tears, White said he never would have fired his gun if he knew a young child was in the front passenger seat.

Johnny Silva, now 10, testified earlier that his mother was screaming when he saw a man pointing a gun toward them. The boy said he curled up into a ball and told his mom that the man had a gun.

In his opening statement, Deputy District Attorney Jeff Dusek said Silva was close to her home when she pulled out of the Old Grove Shopping Center off state Route 76, forcing White -- who was going to a grocery store with his wife -- to take evasive action.

As White turned into the shopping center just after 9 p.m., Silva pulled up behind and followed him into the parking lot.

Silva started screeching her tires and tailgating White, "just being a jerk," the prosecutor said. He said Silva had alcohol, marijuana and methamphetamine in her system as she encountered White and his wife.

After driving into the lot, White for some reason stopped his car and Silva pulled up so close to him that he couldn't open his door, Dusek said.

Her son saw White pull out a gun and point it at him, prompting his mother to call 911, the prosecutor said.

He said White did not show his badge or identify himself as a police officer before backing up.

As Silva backed up her car, it made slight contact with White's car and he opened fire, the prosecutor said.

After the first shot, it was "boom, boom, boom, boom," for a total of five shots from White's five-shot revolver, Dusek said.

Silva was shot twice in the arm and suffered a broken arm. Her son was wounded on the inside of the left knee.

Defense attorney Rick Pinckard told the jury in his opening statement that Silva initiated the entire incident.

The attorney said the Whites weren't under the influence and were just going to the grocery store when they encountered Silva.

The peace and tranquility of the couple's world collided with the rage and volatility of Silva's world, Pinckard said.

White had his wife call police before the shooting and was doing what officers do when dealing with dangerous people, Pinckard said.

When Silva pulled up next to his car, White pulled out his gun from a holster in his waistband and pointed it at the "threat," Pinckard said.

At the time Silva collided with White, her blood-alcohol level was 2 1/2 times the legal limit, the defense attorney said.

Her blood-alcohol level was measured at .15 percent two hours after the shooting, Dusek said.

Silva pleaded guilty last year to felony child endangerment and misdemeanor driving under the influence. Her sentencing has been delayed until next month so authorities can see how well she responds to substance abuse treatment at a residential rehabilitation clinic.