WITNESSES SAW 2ND CAR ON BRIDGE; TRIO'S AID SOUGHT IN PROBE OF 2 DEATHS.

Byline: Gloria Gonzales Daily News Staff Writer

Good Samaritans who may have stopped near Jacqueline Bickmann's car on the night she and her 4-year-old son died could help police determine when the pair plunged 100 feet from a freeway overpass.

California Highway Patrol officers discovered the bodies of Bickmann and her autistic son, Garett, at 3:15 a.m. Aug. 6, at the base of the overpass connecting the 118 and 23 freeways. The officers had pulled over when they saw Bickmann's white GMC Jimmy, which was on the freeway shoulder with its emergency lights blinking and a flat right front tire.

Since then, investigators have sought information from motorists who might have seen Bickmann. They received several tips, including information from a father and son who said they saw a light blue, 1995 or '96 Honda Accord parked up behind Bickmann's vehicle.

``We have a father and a son going on fishing trip who called in and said they saw a car stopped there at about 2:15 a.m.,'' said Ventura County sheriff's Capt. Larry Robertson. ``The son is enamored of vehicles, so he noticed the cars, and was able to give a good description.''

The 15-year-old son also reported that the car's driver was a dark-haired white man, and two other occupants sat inside the car.

``More than likely, they saw . . . good (Samaritans) who pulled over and stopped to see if they could help,'' Robertson said. ``We want to know did they meet the mother and son, and go on their way? Or did they get to the car after mother and son had gone over the side?

``We believe it was . . . good (Samaritans) because there were valuables that were left alone in the car, nothing in the car was messed with.''

Investigators ask that the driver, or the passengers, of the Honda Accord that stopped near Bickmann's car, call the Sheriff's Department at [phone].

Robertson said Tuesday that evidence continued to support one of two theories: that the pair accidentally fell from the bridge; or that Bickmann intentionally leapt from the overpass with her son.