Investigators on the trail of a notorious serial killer say they are close to locating the remains of yet another child victim, who disappeared four decades ago.
Authorities plan to excavate a site in Ventura County in hopes of finding the remains of Roger Dale Madison, a 16-year-old boy whom Mack Ray Edwards confessed to stabbing.
In 1970, Edwards, a 51-year-old heavy-equipment operator, told Los Angeles police that he had killed six boys and girls over a 15-year period. He later told a Los Angeles County jailer that the real number of victims was closer to 18.
Police believe he buried the children near the freeway construction sites where he worked during California's freeway-building boom of the 1950s and '60s. Each body they find gives them more information about his methods, which could help link him to other crimes.
Edwards hanged himself in a San Quentin State Prison cell in 1971. But before his death, he provided key details that led investigators to the site where he disposed of his first victim, 8-year-old Stella Darlene Nolan, who disappeared in 1953.
Her remains were discovered in Downey, under 8 feet of earth, near a bridge abutment under the 5 Freeway.
Mack, who moved to Los Angeles from Arkansas, also described killing Madison, a friend and classmate of his teenage son. He told detectives he used a bulldozer to dispose of the youth somewhere along the 23 Freeway in Thousand Oaks when the roadway was under construction.
"It was his intimate knowledge of these often desolate sites, where it was easy to dispose of a body with little danger of discovery, that I think allowed him to kill repeatedly," said Det. Vivian Flores of the Los Angeles Police Department. "His work was a huge part of it. It was essential to his crimes."
Flores would not divulge the exact location of the planned excavation or say when it would begin. But she did describe the site as a compaction hole.
Freeway engineers use compaction holes during construction to determine if the underlying soil can support the structures being built above them.
The description Edwards initially gave detectives was so broad it fit most parts of the freeway, which connects Thousand Oaks and Simi Valley. But after police went public with the long-forgotten cases last year, tips came in that helped them narrow the field considerably, Flores said.
A retired Caltrans engineer contributed a personal log containing notes with precise descriptions of the progress of the freeway construction.
"It had weather, the phase of construction and their locations," Flores said. "It helped us correlate the time period when Roger went missing on Dec. 14, 1968, to what was going on" with the freeway's construction.
It also helped confirm details of Madison's killing and verified details that Edwards had mentioned, like getting his truck stuck in the mud as he buried the boy.
"The logs showed it was raining for the entire week before the murder, which would mean nobody was around at the site," Flores said. "It also helped us pinpoint a location where construction was taking place."
The detectives' next step was to use cadaver dogs. Two sets of search dogs brought in at different times homed in on the same patch of ground next to the freeway, Flores said.
Detectives also got positive readings when they tested soil in a machine that identifies chemicals found in decomposing human remains. They also used ground-penetrating radar, which showed an anomaly adjacent to the locations where the dogs had reacted.
The upcoming operation may take more than a week and is likely to include several dozen law enforcement and forensics personnel from agencies including the LAPD, Pasadena police, Los Angeles County and Ventura County sheriff's departments, Caltrans and the FBI. Forensic scientists from as far away as the Oak Ridge National Laboratory in Tennessee also will be on hand.
The effort to reconstruct what happened on the 23 Freeway began several years ago, prompted by the determined and enterprising work of Pasadena author Weston DeWalt.
He was researching the 1957 disappearance of 8-year-old Tommy Bowman in the Arroyo Seco when he made the link between a sketch in a police file of a man seen following the boy to a newspaper photo he had seen of Edwards being led into a courtroom in handcuffs.
In 2006, DeWalt interviewed Edwards' widow and other relatives. A family member showed him a letter from Edwards to his wife, Mary, written when he was on death row.
"I was going to add one more to the first statement" to the LAPD, he wrote, "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."
Last year, the LAPD, Pasadena and Torrance police, the state Department of Justice and the Los Angeles County Sheriff's Department went public with their investigation into the decades-old child murders.