The story of Friedrichs - long forgotten by many in Delaware County - has become a rallying cry for legislation to require more stringent background checks of teachers.
With his Interboro recommendation, Friedrichs landed a teaching job in Fayette County, W. Va., and eventually became an elementary school principal there.
In 1997, a 12-year-old boy was found dead in Friedrichs' cabin during a fishing trip on the New River. Ultimately, he was convicted of poisoning the boy with chloroform. In a separate trial, Friedrichs was found guilty of sexually abusing two more former Fayette County students.
As recently as last month, U.S. Sen. Pat Toomey (R., Pa.) shared the convicted killer's tale on the Senate floor, telling his colleagues that "shockingly and so disturbingly, the school helped this teacher to get a new job."
Reached by phone at home in Florida, Castle said "no one knew" of Friedrichs' suspected abuse "until a parent came in one day and said something to me." He said the matter occurred long ago and then hung up.
Speaking through officials at the Mount Olive Correction Complex in West Virginia, Friedrichs declined The Inquirer's request for an interview.
Police never investigated the claims against Friedrichs in Interboro. Much of the evidence of abuse is contained in interviews of former students and parents by a private investigator in 1999.
A federal civil suit filed against Interboro by a sexual-abuse victim in West Virginia provides some documentation of the district's alleged complicity. The suit, settled in 2007, includes Friedrichs' one-sentence resignation letter and Castle's handwritten recommendation.
Marise Stillman, whose two sons Friedrichs allegedly fondled, said she confronted school officials only to watch him disappear from the district in 1973. Sitting in her Prospect Park home late last month, she teared up at the thought that decades later, Friedrichs was able to kill a boy.
"I felt a tremendous guilt that I hadn't been able to stop him," she said.
More than 20 years after Friedrichs moved to West Virginia, Jeremy Bell was found dead in Friedrichs' fishing cabin. The medical examiner concluded the boy choked on his own vomit. Authorities did not charge Friedrichs for six years.
Frustrated, Bell's family hired Erie private detective Daniel Barber. He immediately suspected Friedrichs was responsible for decades of abuse and headed for Delaware County.
Friedrichs grew up in Collingdale, just outside Interboro's ring of primarily working-class towns. After graduating from West Chester University in the mid-1960s, he found a job at Prospect Park.
In an interview with The Inquirer, Barber said about 20 former Interboro students admitted their former teacher had molested them in some manner.
Friedrichs was a "preferential pedophile," Barber said, attracted to blond-haired boys 9 to 12 years old.
One such boy was fifth-grade student Eddie Bartholomew. In a recent interview, Bartholomew described Friedrichs' trying to show him how to tuck in his shirt. "He went to do it, and I just kind of did a sidestep turn," Bartholomew, now in his 50s and living in North Jersey, said. "That's the last time he tried anything. I count myself among the very fortunate."
Barber said Friedrichs oversaw the school crossing guards, many of them his handpicked "golden boys." He often asked some of the students to stay after school, including one who later told Barber he was raped in a book closet.
Stillman said she learned in 1973 that Friedrichs had fondled two of her sons on separate occasions in his class. After sending the boys to a psychologist, she said, she and her husband met with Castle and Interboro Superintendent McDonald Egdorf, who has since died.
"The superintendent said to me, 'Well, Mrs. Stillman, just what is it you want us to do about this?,' " she recalled.
Nothing came of her meeting, she said.
Stillman said the Interboro school board also failed to address her concerns, which she voiced at a public meeting. David Connery, board vice president then, said he had no recollection of Stillman's making such a statement.
She said she also tried to press charges through the local district judge, which she said was how such matters were pursued at the time. But her son only cried when he spoke to the judge, who said he couldn't proceed.
Stillman was unaware that after Friedrichs resigned, he moved to West Virginia. Then, in 1999, Barber, the private investigator, knocked on her door. He told her a boy in Fayette County had died in Friedrichs' care.
Searching for justice
In 2002, Friedrichs was sentenced to 31 to 65 years in prison for abusing two former West Virginia students in the 1990s. The next year, he was charged in the murder of Jeremy Bell. Investigators found evidence that just before the fishing trip, Friedrichs had bought chloroform.
Further tests showed the chemical was in the boy's blood. Friedrichs, who claimed the boy drank the chloroform by accident, was convicted in 2005 and sentenced to life in prison.
Legislation to help keep predatory teachers from simply relocating was spurred by a 2004 Philadelphia Weekly series on Friedrichs.
Harrisburg is considering measures introduced by Rep. David Maloney (R., Berks) and Sen. Anthony Hardy Williams (D., Phila.), who first introduced bills in 2006. Both proposals would require potential school employees to disclose any reports of sexual misconduct when applying for a job. And schools would have to disclose such reports to any educational institution that inquires about a potential employee.
U.S. Rep. Mike Fitzpatrick (R., Bucks) introduced the Jeremy Bell Act in 2006 and 2011. It would require districts to conduct criminal background checks and withhold federal funding from schools that knowingly help a teacher suspected of abuse find a new job. Toomey has similar legislation pending in the Senate.
"When I learned of the case, I reached out to Jeremy's father," Fitzpatrick said. "We had a number of telephone conversations. Because Jeremy's father was searching for justice, I introduced a bill in Jeremy's name."