It was among the most brutal Southland homicides in recent memory: On a sunny Sunday afternoon last fall, two men jumped out of an SUV and set Marcial Sanchez on fire, in full view of a crowd on Cesar Chavez Boulevard in East Los Angeles.

The 52-year-old factory worker was engulfed in flames and burned over 70% of his body. He died hours later at a hospital.

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UPDATE:
Sheriff's investigators have scheduled a news conference for Tuesday at 11 a.m. at the homicide bureau in Commerce to request information from the public in the Marcial Sanchez case and discuss witness safety. Investigators can be reached at (323) 890-5500.

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No one who saw Sanchez's killing reported it to police. The hush was so complete that for months the Los Angeles County Sheriff's Department considered the case a possible suicide.

The slaying, like so many drive-by and walk-up shootings, was committed in a brazen, conspicuous way precisely because it was designed to stop witnesses from coming forward, authorities said.

"They definitely have people terrified," said Sheriff's Sgt. Shawn McCarthy.

The episode stands out as an especially gruesome example of the massive problem of witness intimidation. Over and over in Los Angeles County, killers commit such daylight shootings to cement their control over the streets.

"They show the average citizen that they [the killers] can do things and get away with it," said Sheriff's Lt. Al Grotefund.

The problem is a factor in no less than "all gang-related crimes," he added.

Gary Hearnsberger, head deputy of the district attorney's hard-core gang division, said reluctant witnesses are so ubiquitous in the world of felony gang cases that practitioners like him have a hard time quantifying it.

"We deal with it every day. . . . It's like breathing air for what we do," he said.

The reluctant witness is the primary reason that the rate of solving most 2007 homicide cases in Los Angeles County stood at about 41% at year's end, law enforcement experts say, leaving the majority of killers unpunished.

Police agencies and the district attorney's office relocate witnesses regularly for safety, a step that Hearnsberger says is an effective way to protect people. But many witnesses still balk.

"Witnesses are terrorized and afraid to come forward," he said. And perpetrators try to keep it that way. "There are clearly homicides where they are trying to send messages," he said.

Sanchez, an immigrant from the Mexican state of Puebla, was the father of three adult children and grandfather to four young children.

Detectives say he owed as much as $23,000 to shady lenders who were charging higher and higher interest rates, and they consider it possible that the debts may have made Sanchez the target of some gang, organized crime ring or loan shark.

The message might have been, "You burnt me for money, I'll burn you," said homicide Det. Q. Rodriguez, an investigator on the case.

Sanchez and his second wife worked together at a tortilla factory. They were on their way to pick up a co-worker in East L.A. before the night shift that Sunday, Oct. 7, detectives said.

A short distance from the co-worker's house, Sanchez asked his wife to drop him off at a liquor store. He wanted to buy a beer for himself, he said, and a Gatorade for her.