As a media throng watched from behind yellow crime scene tape, dozens of law enforcement and forensic experts on Monday began excavating a small piece of land along the 23 Freeway in Moorpark where police believe child serial murderer Mack Ray Edwards buried 16-year-old Roger Dale Madison 40 years ago.

The gruesome dig, which began at 10 a.m., is focused on the southbound Tierra Rejada Road offramp, where four corpse sniffing dogs have indicated human bones are probably buried. To zero in on the exact location, police are also using the services of Caltrans ground penetrating equipment to check for anomalies, as well as the services of an archaeologist who used a photo ionization detector that sniffs out decaying human bones.

For up to ten days, as the dig continues, the Moorpark interchange will look like a makeshift archaeological dig replete with tents, trailers and dozens of police vehicles. The LAPD is streaming a live video feed of the project on its Web page at www.lapdonline.org.

Serial Killer Mack Ray Edwards. Click on image above for photo slideshow of the body dig underway.

The late serial killer, Edwards, was a heavy equipment operator who confessed to LAPD detectives in 1970 that he stabbed the Madison boy to death in an orange grove on December 14, 1968. The interchange of the 23 Freeway at Tierra Rejada Road is about 25 miles west of Sylmar, where Madison was last seen alive.

The notorious Edwards, a married father of two adopted children, also admitted nearly 40 years ago to killing five other children, including one of his own relatives, between 1957 and 1968. But he was only charged with the murders of three, and some bodies were never found.

Edwards was never charged with the murder of Madison. He told police of the era that he didn't know exactly where on the 23 Freeway he dumped his body. Eerily, he later told a reporter that he did know the location but didn't divulge it because, the killer claimed, Madison's parents were poor and couldn't afford a burial.

Victim Roger Dale Madison is believe to be buried near the 23 Freeway

Edwards committed suicide in 1971 while awaiting execution on San Quentin's Death Row. Police believe he may have been responsible for as many as 20 killings.

“If we find remains, it will be an active crime scene,” said Los Angeles Police Captain Jim Miller of the Van Nuys Station, flanked by at least a dozen law enforcement officials. Miller said the dig was organized to give “closure for the family.”

“His parents went to their grave not knowing what happened to their son,” he said.

An orange Caltrans front-end loader tore through the hard ground an inch at a time as a forensic anthropologist watched intently, standing with a team of experts who began sifting through the soil for bones. Over 20 FBI agents from the evidence response team, trained in identifying, collecting and preserving evidence, were on hand.

They will use the front-end loader to remove the top layer of soil; then they will dig with shovels, trowels and toothbrushes.

Given that Edwards is possibly responsible for around 20 murders, investigators and author Weston DeWalt, who brought Edwards to the attention of the police as a suspect, says it is possible a different victim may be buried at the site.

“There are no guarantees,” says DeWalt, a pleasant man in his early 60's. DeWalt says one victim might have been a 20-year-old woman who disappeared from her church office in Granada Hills three months before Madison disappeared. DeWalt theorizes that Edwards may have met the young woman through his daughter, who played the organ at local churches.