OCEANSIDE, Calif. -- Police Thursday disclosed more findings from their probe into an officer-involved shooting that wounded an unarmed woman and her 8-year-old son outside an Oceanside home-improvement store last month.

Investigators have determined that a near-collision on Old Grove Road evidently led to the March 15 confrontation during which off-duty San Diego police Officer Franklin White opened fire on 27-year-old Rachel Silva's car, Oceanside police spokesman Kelan Poorman said.

Shortly after 9 that night, White and his wife were southbound in their black Mercury sedan when, according to a witness, Silva steered her Honda out of a gas station directly into their path, forcing the officer to swerve sharply to avoid a crash, Poorman said.

White, 28, then continued down the road for a short distance and pulled into a parking lot outside a Lowe's store, according to investigators.

As he did so, Silva -- whose son was seated next to her -- reportedly tailgated him, revved her engine and yelled, prompting White's wife, a Carlsbad police dispatcher, to make a 911 call, Poorman said.

The off-duty officer stopped his car, and Silva pulled alongside. White responded by displaying a pistol and backing his car away as Silva, in turn, made an emergency call, reporting a man with a gun.

She then reversed her car as well, sideswiping White's in the process. At that point, the officer opened fire through his closed driver's side window, shattering it, Poorman said.

The first bullet went through the darkly tinted front passenger window of Silva's vehicle, striking her son in the left leg, and four others pierced her windshield. Two of those slugs struck her in the upper right arm.

Silva and her child both spent about five days in a hospital.

There have been no arrests in the case.

White, who has been an SDPD officer since October 2005, is on paid administrative leave. He has not spoken publicly about the incident.

Silva, while claiming memory lapses due to her injuries, has insisted that she did nothing that could justify the officer's actions, which she has labeled "attempted murder" in interviews with news crews.

The night of the shooting, Silva was driving on a suspended license and facing a drunken driving charge in connection with a prior arrest. Police ordered her blood taken at the hospital.

White -- who, like Silva, is an Oceanside resident -- was not required to undergo sobriety tests.

Silva and her ex-husband have each filed a claim against the city of San Diego, seeking unspecified damages.

Luis Silva, a Camp Pendleton Marine, was on deployment to Iraq at the time of the shooting of his son and former spouse. He returned to Oceanside a short time later.