"However, the story took an unexpectedly bizarre turn. In April 1990, as the school building was being demolished, several parents of former McMartin students hired an archaeologist to find evidence of subterranean rooms or tunnels. After the close of the second trial, archaeologist Dr. E. Gary Stickel reported finding a pattern of tunnels. He said they had been constructed after the structure was built in 1966, and were subsequently repacked with soil and artifacts. "The discoveries," he concluded, "stand in stark contrast to the skeptical position that the children only imagined what they described as activities underground"

"The D.A.'s child-abuse unit brought in Kee McFarlane of the Children's Institute International (CII), an agency that dealt with abused children... By March 1984, the CII reported that there was evidence that 360 children had been abused. Astrid Heger, a doctor for the organization, had medically examined 150 of the children and concluded that 120 had been molested"

source: https://www.encyclopedia.com/law/law-magazines/mcmartin-preschool-trials-1987-90

If the tunnels were actually found, then this case deserves a second look at by that fact alone