On March 23, 1957, his son Tommy, 8, vanished at the end of a brief hike.

"I'll beat you to the car," Tommy told his two cousins before scrambling out of their lives forever.

The Redondo Beach boy went around a corner and then was just gone.

Massive searches were organized. For nearly a week, police and residents thought they were looking for a lost child. Stories in the Daily Breeze and newspapers throughout the Los Angeles region tracked every development.

Weeks later, with all leads exhausted, the crisis of Tommy's disappearance settled into something of a black hole. There was nothing more for his parents and siblings to do but return to their home on Irena Avenue.

Five decades later, a Pasadena man obsessed with ending Eldon Bowman's torment by uncovering the truth behind Tommy's disappearance has reached grisly and disturbing conclusions about what happened that afternoon. And the police say he's got it right.

Furthermore, the revelations of author Weston DeWalt could precipitate breaks in a number of other cold cases involving child victims throughout Southern California.

After more than two years absorbed in research on Tommy's disappearance, DeWalt is convinced the boy was abducted that Saturday evening and murdered by Mack Ray Edwards, then of Azusa, during the course of a long career as a serial sexual abuser and murderer of children.

DeWalt is not alone in his theory.

"I absolutely believe he's responsible for the disappearance of Tommy Bowman," said Detective Vivian Flores of the Los Angeles Police Department's Cold Case Homicide Unit. "He's gotten away with it. He can't win and I won't let him."

Not that Edwards is around to take his punishment. He committed suicide in 1971 in San Quentin state prison.

From 1953 to 1968, Edwards is known to have killed half a dozen children: * Stella Nolan, 8, was abducted from her home in June 1953, sexually abused, strangled and left for dead in the Angeles National Forest. * Donald Baker and Brenda Howell, both 11, left Azusa on a bike ride in 1956 and never returned. Their throats were slit and their bodies were dumped off Mount Baldy Road. * Gary Rocha, 13, was found shot to death in his Granada Hills home in 1968. * Roger Madison, 16, left his Sylmar home on his motorcycle one month later and was never seen again. * The body of Donald Allen Todd, 13, of Pacoima was found shot to death the following spring under a footbridge not far from his home.

Police now believe he's responsible for Tommy's disappearance and consider him a "person of interest" in the cases of up to 13 other missing children. An end to the crimes

On March 6, 1970, Edwards walked into the LAPD's Foothill Station with a loaded handgun and turned himself in for kidnapping three young sisters in Sylmar, where he had been living. The girls had recognized Edwards and, after two escaped, the killer knew his years of mayhem were near an end.

Donald Baker was Edwards' neighbor, Brenda Howell his wife's younger sister and Roger Madison one of his adopted son's schoolmates. Their bodies were never found.

Edwards confessed to all six murders.

He wanted the death penalty, and a jury delivered the sentence. But death didn't come quickly enough. After several failed attempts at suicide, Edwards finally hung himself with a television power cord while on death row.

Decades after the newspapers and their readers moved on to new atrocities, there are men and women for whom these children's names are daily material, their unanswered injustices stretching through time to demand answers.

There are people like Detective Diane Harris, who handles missing persons cases for the Los Angeles County Sheriff's Department.

"I keep them in the back of my mind -- they're always there," Harris said of her child cases. "I can actually even tell you what their names are without looking at them."

Flores, the LAPD detective, keeps her children with her at all times. In her LAPD office, at home or in her car, the detective doesn't let the thick binders with missing children's names printed on the covers out of her sight.

During the two years of DeWalt's investigation, he has worked with Harris, Flores and retired homicide investigator Bill Gleason, now a consultant for the Department of Justice.

"I've never met Tommy Bowman's father, but to find out what happened, to let him know where his kid is and maybe bring his body home, is more satisfying," Flores said.

Police, then and today, didn't buy the story Edwards told them. They believed there were more -- possibly many more -- victims.

All share the opinion that Edwards abducted Tommy, and are considering whether he was involved in other disappearances: Bruce Kremen, 7, from the Angeles National Forest in 1960; and Karen Tompkins and Dorothy Brown, both 11 and from Torrance, in 1961 and 1962.

They were especially skeptical of Edwards' claim to have stopped killing during the 12-year span from 1956 to 1968.

"I know there are times when they know what they're doing is wrong, and they don't want to do it, but they have this compulsion to," Harris said. "He could have been not killing people during that time frame, but I doubt it." Making the case

Police say they know Mack Ray Edwards, born in Arkansas in 1918, sexually molested at least one girl before marrying a young wife in 1946 and moving to California a year later.

A heavy equipment operator, Edwards worked on several of the freeways now crisscrossing Southern California.

"It's the perfect place for a man who's a serial murderer to bury the kids he's killing," Harris said. "He knows where the holes are, he knows where the concrete is being poured."

Edwards made no mention of Tommy Bowman in his original confession, but later bragged in prison that his murders numbered 18, DeWalt said.

Ultimately it was a rough sketch and a bizarre letter smuggled out of prison before his suicide that convinced DeWalt that Edwards had killed Tommy.

He made the first tenuous connection between the two when he came across stories about the murderer.

He had a feeling of déjà vu when he saw a photograph of Edwards, and recalled an amateur sketch made at the time by Claudine Clarke of Altadena.

"I studied the sketch; I studied the photographs," DeWalt said. "I went from one to the other, warning myself against what appeared to be too easy a reach."

His suspicion was strong enough to begin looking into Edwards' history. But police said they needed more than a sketch with an uncanny resemblance.

While Eldon Bowman and his family retraced their steps looking for Tommy, the boy had continued south until, adjacent to the Jet Propulsion Laboratory, he ascended a trail to the west end of Altadena Drive.

Two witnesses saw a boy believed to be Tommy near the trailhead on Altadena Drive. Further east, another woman in the 700 block saw a boy matching Tommy's description crying as he walked eastbound along the street.

Moments later, she saw a "very tan, unkempt man" matching Edwards' description casting furtive glances side to side and moving "at a good clip" behind Tommy, DeWalt said.

Across the street, Claudine Clarke reported some moments later seeing the same man -- but with one discrepancy. Clarke described a man in a white T-shirt; her neighbor said he was wearing a plaid shirt.

In old photographs of Edwards taken before his surrender, DeWalt said he can be seen wearing a plaid shirt buttoned over a white T-shirt. He theorized that as Tommy drew closer to Lincoln Avenue and busier streets, Edwards removed his overshirt to free his movements and make the abduction.

The investigation's shocker came from a letter seized in an October search of the home of Edwards' widow. A coded confession

In a strange "anti-confession" smuggled out of San Quentin before his suicide, Edwards recanted much of his confession and said he was taking the heat for a man he identifies only as "Billy the cripple." Police investigators unanimously dismiss the anti-confession as an invention born of Edwards' psychosis.

But later in that same letter, Edwards drops a bombshell.

"I was going to add one more to the first statement," DeWalt recounted Edwards writing of his original confession. "And that was the Tommy Bowman boy that disappeared in Pasadena, but I felt I would really make a mess of that one, so I left him out of it."

Police believe that is Edwards' coded confession to killing Tommy.

"That right there puts me over the top," Flores said. "If he didn't know about Tommy Bowman, he wouldn't have mentioned it."

Eldon Bowman never stopped wondering what happened to Tommy, and laments that Tommy's mother, Mary, died several years ago, still wondering.

After 50 years of unextinguished hope, the 85-year-old isn't ready to embrace entirely what DeWalt and police now believe happened to his son.

"It makes the most sense, as much as I don't like to think about it," said Bowman, who now lives in Simi Valley. "It isn't finalized, but it probably is the best explanation anyone has come up with so far."