KING CASE AFTERMATH: A CITY IN CRISIS : Officials Discern No Pattern in 4,000 Arson Fires : Blazes: The crime is hard enough to prove in normal times. There were only 10 complaints filed after 600 buildings went up in flames in Watts riots.

There has been no discernible pattern in the nearly 4,000 arson fires that have ripped through Los Angeles since Wednesday, weary fire officials said Friday while acknowledging that they will only be able to investigate a fraction of the deliberately-set blazes.

Rioters, alongside looters and bystanders, have boldly hurled Molotov cocktails, ignited gas puddles and thrown burning bundles of newspapers into countless buildings, touching off three days of blazes.

Deputy Fire Chief Rey Rojo, who spent six hours in a helicopter Thursday, said the fires revealed only a haphazard patchwork of ashes and flames.

“You do a flyover and see what appears to be a whole block gone, and then you go to another area and one building got hit,” Rojo said. “I don’t see how anyone can draw a conclusion and say it was following a pattern.”

Last year fire officials investigated 1,000 suspected arson blazes. In the last three days alone, arsonists have ignited about 3,700 fires. History suggests that only a minuscule number of those responsible for these fires will be convicted.

Arson arrests after the 1965 Watts riots numbered only 27 despite 600 building fires. Ultimately 10 court complaints were filed.

“The fires that have the potential for solution, yes, we will work on,” said Los Angeles City Fire Department Chief Donald O. Manning. “Those that would merely be an effort in futility we obviously won’t do that. In normal times we don’t have enough investigators for all suspected arson fires.”

Officials said they have not even been able to start the painstaking process of investigating the arson fires, which are often difficult crimes to prove.

Overwhelmed by the enormous effort of battling scores of fires every hour, city fire officials have not dispatched any of their 19 investigators to the building ruins because of safety concerns. With firefighters assaulted by rocks, bottles and gunshots since Wednesday, an investigator methodically probing through rubble would be a slow-moving target for violence.

Furthermore, Deputy Fire Chief Davis Parsons, whose command includes the department’s arson unit, said his exhausted staff had not even considered how to devise a plan to deploy the few investigative resources at hand. Officials also have not completed a survey on how many buildings have burned and how badly.

“The magnitude of this travesty is beyond the scope of our investigators,” he said.

When rioting calms, arson probes will begin with the aid of a new task force. Los Angeles Dist. Atty. Ira Reiner announced Friday that arson investigators will be included in a “civil disorder task force” he is setting up.

“We are in the process of contacting the Los Angeles Fire Department, the County Fire Department, LAPD, and the Sheriff’s Department to set up a joint effort for investigation and prosecution of arson related to the riots that have been going on,” Reiner said.

A city fire official said the federal Bureau of Alcohol, Tobacco and Firearms has also offered to lend investigators to supplement the arson efforts.

Once investigations begin, authorities will return to the scene, look through debris, try to find out where fire erupted and interview witnesses. But it may be hard going.

“In situations like this where there is just mass pandemonium and mobs, your chances are probably pretty slim that you’re going to actually apprehend someone and prosecute them,” said Battalion Chief Carlton E. Calloway, commander of the department’s dispatch center. “Arson is a difficult crime to prove normally, but in a riot or unrest like this is, it’s probably less likely.”

Lt. Raul Vega of the Los Angeles Police Department’s Northeast Division, said he was on the scene when at least one fire was set--and yet he could make no arrest.

That case involved a dentist’s office on Vermont Avenue, where a large crowd was gathering Thursday afternoon. When he arrived, he said, more than 500 people were milling about the corner. While his officers tried to disperse the crowd, he noticed a small whiff of smoke rising from a broken office window.

“I requested the Fire Department, but within minutes the smoke turned black and the fire was on its way,” he said. “Whether someone tossed some incendiary device in there while we were dispersing crowds, I couldn’t tell.”

Because communications between police and fire authorities have focused solely on controlling the rioting and fires, it was not known Friday how many of the more than 4,000 arrests were arson-related.

Pasadena Fire Chief Kaya Pekerol said several people in his city were arrested for arson including one man who was caught after hurling a Molotov cocktail through a window.

“Fortunately, the fire didn’t really get going,” he said.

Even as fire officials tracked the outbreak of fires--that first erupted in South Los Angeles Wednesday and spiraled outward Thursday and Friday--they could not figure out a pattern and do not know whether teams of arsonists systematically set the blazes.

James E. Blancarte, president of the city Board of Fire Commissioners, said his impression is that the arsonists included “people who are setting arson fires by driving around with large amounts of flammable liquids,” and looters who torch a store after they empty it.

Greg Sandoval, a USC student, said he witnessed a loot-and-torch blaze at the Sorbonne Liquor Store near campus Wednesday night. A group first hauled off bottles of liquor in shopping carts and was joined by other looters. When Sandoval returned to the store an hour later, the looting had subsided but the store was being torched.

“I saw some kind of tanks or tubs as they were walking,” Sandoval said. “They were scattering alcohol, or whatever, all around, and it was already smoking inside. There already was a fire going.”

The arsonists fled before police arrived.

Investigators probing this week’s fires will also find their tasks complicated because many buildings have burned to the ground, leaving little evidence, and witnesses may be hard to locate.

“We will be looking for people who are eyewitnesses,” said Fire Commissioner Aileen Adams. “We will be reviewing videotapes and collecting them as evidence. But arsons are very, very difficult cases.”

Assistant Chief Parsons, so hoarse from inhaled smoke that he sprayed medication to soothe his throat during an interview Friday, urged residents to call the department’s 1-800-47-ARSON tip line to report incidents.

Times staff writer Laurie Becklund contributed to this story.