The FBI has joined Foxborough police to pursue leads in the case against accused serial pedophile William E. Sheehan, who allegedly molested dozens of children over two decades starting in the early 1960s.
Norfolk County prosecutors said in September that a psychological report found that the former teacher, scout leader, and swim coach was too ill to stand trial. He has not been charged.
But the local case remains open, and federal investigators could be looking at a range of issues, including what Sheehan’s supervisors knew at the time of the alleged abuse and whether others were involved.
FBI spokesman Greg Comcowich confirmed Thursday that the agency is assisting local police.
“We are aware of the investigation, and we are assisting Foxborough police,’’ Comcowich said. “We’ve also consulted with behavioral analysts and other forensic experts.”
The bureau does not usually comment on inquiries, but the spokesman said the FBI confirmed its involvement because of the large number of alleged victims, the extended timeframe of alleged abuse, and the circumstances that led prosecutors to decline to file charges.
Foxborough was stunned in September 2012 when Police Chief Ed O’Leary said eight men had accused Sheehan of abusing them when they were boys during his two decades as a town employee. The number of alleged victims rose to 22, although some of the men say the number is even greater.
Sheehan was charged with multiple counts of indecent assault on a child under age 14 and multiple counts of indecent assault on a child age 14 or older, but the arrest could not be carried out.
When police and prosecutors arrived in Fort Myers, Fla., to arrest Sheehan, they said they found him in a nursing home suffering from the late stages of Alzheimer’s disease.
The self-described victims, now in their mid-40s to age 60, say the assaults occurred at Sheehan’s home, on school property, and at the former Cocasset River Park, among other locations, from 1961 to 1981, when Sheehan moved south.
In 1990, Florida revoked Sheehan’s teaching license based on credible allegations he sexually abused a boy over the summers of 1986 to 1989 at a Punta Gorda scouting camp.
It is unclear what the FBI is investigating.
O’Leary said he held a conference call on July 24 with two agents from the FBI’s Boston office and one from the Behavioral Analysis Unit at its headquarters in Quantico, Va.
“I reviewed the outline of the Sheehan case and we talked about a couple of potential strategies,’’ O’Leary said, declining to name them.
A Boston agent and a forensic interviewer then met with O’Leary and Detective Timothy O’Leary, who is no relation to the chief, on Sept. 4, the chief said.
“We reviewed case notes we had compiled, and they left with notes and documentation to review,’’ he said.
The chief offered no other details, except to say he will reach out to Sheehan’s alleged victims in the coming week.
The FBI’s involvement was greeted as good news by some of the men who have questioned the town’s response to the case and the police investigation.
“It’s encouraging that the police did go a further step,’’ said the Rev. Bill Dudley, pastor of Foxborough’s Union Church. “It shows a real willingness to dig deeper, and I’m hoping they get results.’’
Dudley is one of the dozens of men who came forward last year to say that Sheehan abused them as children. He also heads up the support group Survivors of Sheehan.
Danny Smith of Middleborough was more skeptical. Smith said he hopes the FBI’s involvement results in arrests of others who have hurt children, as he said Sheehan did, “or people who did something wrong by covering up the story.”
Asked how he would feel if it is just an informal review, he said, “I will be crushed.’’
Members of the survivors group have said they do not feel their town is behind them. They held a public meeting last week to discuss their cases, to air concerns, and to share ideas on how to keep children safe. But only one selectman and two reporters attended.
“I don’t think people get how this destroys peoples’ lives,’’ said Kevin Corliss, a 30-year school maintenance employee who said Sheehan began assaulting him when he was 8. “It’s like being victimized all over again.”
At that meeting, members criticized the investigation by a former Foxborough police detective, who is now retired.
“It is very unfortunate that he never returned our phone calls or even talked to us during the investigation,’’ Dudley said.
Chief O’Leary said the investigator was cut back to a part-time schedule after an injury and then retired in May. The case was then handed to another detective.
Mark Sullivan, chairman of the Board of Selectmen, attended the group’s meeting Sunday in the empty church hall. He assured them that the town is on their side and that selectmen are working on policies to protect children.
The survivors group is pressing for passage of House Bill 1455, referred to the Joint Committee on the Judiciary, which would amend the state’s statute of limitations for some sexual-abuse crimes from age 43 to 55 of the victim.
If such protections had been in place in 1998, when Smith first spoke up, Sheehan might have been prosecuted, Smith said.
“There is no doubt that he would have been tried for his crimes,’’ Smith said.
Michele Morgan Bolton can be reached at michelebolton@