Heat-Sensitive Device Might Have Set Off Bomb on Van

Agents investigating the method used in last week’s bombing of a van driven by the wife of USS Vincennes Capt. Will Rogers III have narrowed their suspicions to a heat-sensitive device that could have detonated the bomb with the van’s own engine heat, federal sources said Monday.

Authorities were still reluctant to call the bombing the act of terrorists, but they confirmed Monday that reports have been received of suspicious-looking men, who appeared to be Middle Eastern, spotted near the Rogerses’ La Jolla home in recent weeks.

Rogers gave the order to shoot down an Iranian aircraft, mistakenly thought to be attacking the Vincennes, last July over the Persian Gulf. The downed plane turned out to be an Iranian civilian airliner carrying 290 people. All aboard died.

Last Friday’s bombing is still being treated as “suspected or possible terrorism,” an FBI official said, but other theories range all the way from one or two Iranians acting on their own to disgruntled sailors from Rogers’ ship being responsible.

Question Posed

“What if you have one or two Iranians or other followers of the ayatollah who mount something on their own in response to the ayatollah?” said one source in Washington close to the case. “Or what if you have disgruntled sailors on the ship? Not any of this is being ruled out.”

It appears that no breakthrough is imminent, another source familiar with the investigation said.

However, sources said investigators have come to suspect a heat-triggered device, after finding no obvious signs of a timer or other form of detonating device. They said the explosion now appears to have been caused by one or two pipe bombs placed under the van, directly below the driver’s seat.

One source close to the investigation in San Diego said theories are centering on the possibility that some type of light wood--possibly balsa--was attached to the bomb and the van’s undercarriage. When the motor heated up, it could have ignited the wood and detonated the bomb.

He said the wood could even have been filed down to the size of a match stick or fuse, and that it could have been “just taped” to the explosive or engine.

“It’s been done in the past,” he said. “Apparently the CIA and terrorist groups have used it in the past. The wood would get hot enough and burn, and this would be the igniter.”

He also noted that no traces of the light-weight wood would be left after the resulting explosion. Officials at the scene have found small fragments of a plumber’s pipe and end caps but no clues to the type of detonating device.

“The bottom line on that is that the leads are zip,” the source said.

The sources pointed out that the device detonated when Sharon Rogers slowed to a stop and the motor began to idle, after the van had been driven earlier in the morning. Normally, engine would be cool as it was being driven, and then would heat up as it idled.

An automobile transmission is hottest “when the car is stopped and waiting in traffic,” said one official. “So this theory makes sense.”

Investigators were also checking Monday on reports that as many as three Middle Eastern-looking men were seen in the Rogerses’ neighborhood and asking for the Rogerses’ home.

“There were a couple of guys who asked a paper boy if there was a captain who lived on the street,” one law enforcement official said. “But the kid had just moved in there and didn’t get much of a description of the men. It happened about a week or two before” Friday’s bombing.

John Petrou, a 22-year-old neighbor of the Rogerses who spoke to the FBI, told The Times that he saw two men, whom he described as Middle Eastern-looking, drive into the cul-de-sac where the Rogerses live about two weeks before the bombing. Both acted suspicious, Petrou said.

The first man was driving a gray BMW and drove by on a weekday afternoon, when Petrou was outside washing his car. The second man came by a few days later in a Toyota.

‘Watching Them’

“Usually, people that drive through the neighborhood we all know,” Petrou said. “But these were two guys in separate cars, of Arabic descent . . . I was watching them, but they didn’t look at me. They didn’t look in my face.”

Officials also Monday identified the make of the red car seen making a U-turn and speeding from the bombing scene as a Dodge Omni and said that it had been driving behind Sharon Rogers when the van exploded. They also said that as many as four people were reported in the red car.

Times staff writers Jane Fritsch and Ralph Frammolino contributed to this story from San Diego. Staff writer Ronald J. Ostrow reported from Washington.