Trying to Crack the Car Window Mystery

It could be that teenage pranksters are traversing Los Angeles freeways and shooting BBs at the rear windows of scores of vehicles--shattering 42 of them on Tuesday night and at least eight Wednesday evening.

Or that vandals have stationed themselves on freeway perimeters with powerful slingshots. Or are firing sophisticated nonlethal weapons such as sound waves or lasers.

And these are only a few of the theories being phoned in by members of the public to California Highway Patrol investigators and news organizations.

“Nothing that anybody tells us is crazy,” CHP Sgt. Ernie Garcia said Wednesday. “Nor do we interpret [called-in theories] as crazy.”

Although some tips are certainly stronger than others, the top mystery of the day for hundreds of thousands of Los Angeles County motorists continues to be precisely how vandals have been able to achieve their destructive--and frightening--ends.

After a weekend lull, the freeway sniper attacks are back with a vengeance and CHP investigators are no closer to figuring out where the hits are coming from and who is responsible. So left to their own devices, Angelenos are coming up with their own ideas.

The main reason for all the hypothesizing is that investigators have yet to find concrete evidence pointing to a particular type of weapon. Conventional firearms have been ruled out because officers have not found bullets or gunpowder residue inside the 133 cars and trucks damaged since the rash of incidents began, primarily on East Los Angeles and western San Gabriel Valley freeways, on Sept. 11.

“If you hit a rear window at just the right spot, you can take it out with the lead of a pencil, or the point of a dowel,” Garcia said. “So there are a lot of possibilities.”

That leaves plenty of room for the musings of weapons experts, munitions specialists, conspiracy theorists, armchair detectives, out-and-out crazies and plain old want-to-be-helpful members of the public.

The Los Angeles City Council on Wednesday encouraged the public’s help in solving the mystery, approving a $25,000 reward for information leading to an arrest and conviction in the attacks, on top of the $10,000 reward already earmarked by the Los Angeles County Board of Supervisors.

The CHP, Garcia said, follows up on every tip it gets.

Other CHP officers note, however, that some ideas are, well, more interesting than others.

One caller told a CHP investigator that the vandals were--obviously, he said--using fishing line to hang rocks from overpasses. When a vehicle drove by, the caller explained, it would get hit without the driver seeing anything and without any projectile remaining in the car.

Unfortunately, the investigator patiently explained, a rock hung that way would hit front windows. In these attacks, rear windows are being shattered.

Several tipsters have come up with variations on the same themes.

One caller told a CHP officer that tempered glass was the projectile, since it would not be detected among the shards from the windows. Another investigator was told that a clear marble fired from a slingshot would also shatter right along with a vehicle’s window.

Ice is another theory popular with those who have spoken to the CHP, harking back to classic detective stories in which bodies are found with wounds from a sharp object, although no murder weapon is ever found. The weapon, the sleuths would eventually discover, was an icicle, which melts.

With that in mind, callers have suggested everything from teenagers with ice cubes to space aliens with frozen water pellets. (And no, the CHP is not obliged to investigate theories involving UFOs, Garcia said, making a tiny exception to his no-call-is-crazy edict.)

One person wrote to The Times to offer documentation supporting his contention that “sophisticated equipment is being tested out on unsuspecting automobile drivers.”

Drivers, he wrote, could be “human guinea pigs,” for any of a number of nonlethal weapons, such as “bullets” from hand-held lasers, isotropic radiators, high-power microwaves and infrasound acoustic beams.

Lest that theory be rejected out of hand, one scientist at the Jet Propulsion Laboratory said energy waves cannot be ruled out as plausible weapons in the incidents.

“Projectiles can be very easily detected,” JPL physicist Neville Marzwell said in an interview. “From what I have seen on the news, it doesn’t seem to be an impact-caused phenomenon. A sound wave or a laser or a microwave--I believe these are closer to reality.”

Scientists at JPL, Marzwell said, have experimented with ways to transmit energy into space to power a spacecraft or station. Metal can absorb that energy, Marzwell said. Glass cannot, and shatters when hit by the waves.

Exactly who would have access to the knowledge and equipment needed to carry out a wave-based attack, however, is another matter entirely.

Finally, one caller to the CHP suggested that vandals were using a very basic weapon that could smash a window and not leave a trace: A boomerang.

(BEGIN TEXT OF INFOBOX / INFOGRAPHIC)

The Theories

With the cause of the rash of car window shatterings still a mystery, authorities have received a steady stream of theories. Among them:

1. BBs

2. Iceballs

3. Clear marbles fired from slingshots

4. Rocks tied to fishing line dangled from overpasses

5. Sonar or stealth weapons being tested by unidentified government agents.

Sources: California Highway Patrol, phone calls and mail to The Times