FBI investigators began excavating another well in Linden on Monday, opening a new chapter in the expanding saga involving serial killers Wesley Shermantine and Loren Herzog and their murder-spree decades ago.
Herb Brown, special agent in charge of the Sacramento FBI office, cautioned there is no guarantee that any human remains will be found in the well, located in a rural area off Flood Road in San Joaquin County.
"There is no certainty," Brown said in a news conference Tuesday, adding, "We're optimistic, based on what our experts tell us."
Brown said excavating the 50-foot-deep well will be a painstaking process involving the hand-sifting of dirt and the digging of just five feet per day. The process is expected to take two to three weeks, depending on weather and soil conditions, Brown said.
Flood Road between Escalon Bellota Road and North Waverly Road will remain closed during that period.
"To be quite frank with you, the progress will be slow," said Brown, who promised a "careful, methodical and safe" excavation.
Brown was careful to emphasize that the FBI was not involved in the excavation of another Linden well early last year, in which the San Joaquin County Sheriff's Department drew heated criticism for possibly damaging or commingling remains of victims.
That effort unearthed more than 1,000 bones and fragments that anthropologists later connected to three victims and a fetus.
The FBI became involved after that excavation.
This time, Brown said, the FBI is being assisted by multiple agencies, excavation experts, forensic anthropologists and engineers.
"We're going to do this right, and not first," Brown said.
Brown said the effort would involve more than two dozen investigators. He declined to say how much the excavation could cost.
"Expense is not the issue here," he said. "We will bring to bear all the resources of the FBI to make sure we do the right job for the right reason."
Brown said any remains discovered at the site would be packaged and sent to an FBI lab in Quantico, Va. He said families of missing people should stay in touch with their local law enforcement agencies for word on whether any matches are made.
Asked whether this site was identified based on information provided by Shermantine who is on death row for his role in the killings Brown said only that a variety of investigative factors played a role.
"If you rely on the statements of a convicted killer (and that only), that is a perilous path you take, and we will not take that path," Brown said.
The first well excavation, in February 2012, began after Shermantine told Sacramento bounty hunter Leonard Padilla and a Stockton newspaper reporter of a "bone yard" filled with victims.
Shermantine was convicted of four killings in the 1980s and 1990s; Herzog was convicted in three of those. However, authorities have long believed that the "Speed Freak Killers" so called because of their methamphetamine-fueled destruction were responsible for many more.
The latest to join the confirmed list of victims were JoAnn Hobson, who was 16 when she disappeared from east Stockton in 1985, and Kimberly Billy, who was 19 when she went missing from the same area a year earlier. They were two of three victims whose remains were pulled from the first Linden well; the third victim and the fetus have not been identified.
Herzog was 46 when he hanged himself last January, not long after being paroled from prison. The suicide followed a visit by Padilla in which the bounty hunter says he told Herzog that Shermantine was providing new details on the killings.
Shermantine has maintained his innocence, arguing Herzog was solely responsible for the deaths. He was temporarily taken off death row last summer and escorted to Linden, where he tried to identify burial sites for law enforcement. He has received some of the $33,000 Padilla promised him for the information.
Also attending Monday's news conference was state Sen. Cathleen Galgiani, a Stockton Democrat who has described herself as an advocate for the victims' families and helped arrange for Shermantine's visit to the area.
"I'm pleased the FBI is involved. We can't change what's happened in the past," she said, but added that she is confident the FBI will show the "highest amount of respect and dignity to the families and victims themselves."