EAST MILLINOCKET, Maine — The FBI probably could not take up the 32-year-old investigation of the Joyce McLain homicide even if state police asked them to, according to the FBI’s regional spokesman.

The FBI has “an excellent relationship with state police but the simple fact is that it just does not appear that federal law or our own guidelines allow us to initiate our own murder investigation,” said Greg Comcowich, a special agent with the FBI in Boston.

Comcowich echoed recent statements by state police Col. Robert Williams during an interview with Comcowich on Friday. He and Williams were both trying to gently reject a request made by the victim’s mother, Pamela McLain, saying they sympathized with her plight.

Speaking after the memorial ceremony on the anniversary of the Aug. 8 homicide, McLain said she wants the FBI to do more than review the homicide case file. McLain, who said she met briefly with Williams and other state police officers on Aug. 2, said she wants FBI agents to join the investigation as equal partners in the probe.

“I am asking for them to come on board to work as a team, together, going through that file thoroughly, and to go talk to people named as suspects and weed them out and review the evidence found. And talk to [other] people involved in it — not just a review. A review is talk,” McLain said.

An Internet petition seeking FBI involvement in the case drew more than 4,000 signatures. McLain has been pushing for more FBI involvement in her daughter’s case since 2010.

Under federal law, the FBI can investigate homicides only in connection with crimes involving interstate travelers, on federal highways or federal lands such as national parks; with violations of the Racketeer Influenced and Corrupt Organizations Act and the International Traffic in Arms Regulations and other multistate crimes; felony killings of law enforcement officers; or with serial killers, Comcowich said.

Two meetings within the last three weeks between Williams, other state police, and Todd Difede, the supervisory special agent in Portland, and other FBI agents revealed none of those things, Comcowich said.

A 16-year-old sophomore at Schenck High School, Joyce McLain was killed sometime during or after the night of Aug. 8, 1980. She was last seen jogging in her neighborhood. About 35 hours passed, and a rainstorm came, before searcher Peter Larlee found her body in a clearing near electrical lines close to the school’s athletic fields. Her head and neck had been hit with a blunt object.

The homicide drew national attention on the syndicated television show “Unsolved Mysteries” in 1989, in which Larlee re-enacted his awful discovery, and in People magazine, which in April 2009 featured the discovery of forensic evidence found during an exhumation in 2008. The “Unsolved Mysteries” episode is still available on the Internet.

No arrests have been made.

McLain declined to discuss Comcowich’s statements on Friday. She has said that she was working with people to increase the FBI’s involvement in the case.

The FBI was involved previously in the case, providing state police years ago with a profile of the killer or killers, Williams said. State police do not hesitate to seek help from other agencies when they feel it necessary, Williams said. The FBI became involved almost immediately in the search for Ayla Reynolds, the Waterville toddler who went missing in December from her father’s home, he noted. That investigation continues.

Williams stressed that the McLain investigation is far from dead, with detectives still reviewing the case periodically and chasing down new leads. State police have traveled out of state several times to interview persons of interest connected to the case.

The FBI can continue to advise state police on the case or provide expertise or facilities that state police lack, but the FBI review showed no lack of expertise or skills on the part of state investigators, Comcowich said.

“We are happy to help in any way we can within the limits we have,” Comcowich said, “but Maine State Police has the resources and has put the dedication into doing as much as any law enforcement agency can do.”

State police have declined to discuss in specific detail exactly how far their efforts have reached, but they have included the exhumation, interstate trips and occasional sweeps through the Katahdin region in which they have done door-to-door interviews and new interviews with case witnesses. Residents raised money for a reward for information leading to the arrest of McLain’s killer.

“We’re still plugging away at it,” state police Detective David Preble said on the case’s 25th anniversary. He was the fifth primary detective to be assigned to the case, although many others have assisted, from troopers to police officers and prosecutors.

Of suspects, there’s a “good dozen or so,” he said. “Realistically, I cannot go to sleep at night saying, ‘This is definitely the guy.’”

The case was troubled from the start by a torrential downpour and the passage of 35 hours between Joyce McLain’s disappearance and discovery, investigators have said. Investigators believed then that any fibers, hairs or shoe prints that could have been left behind by the perpetrator were washed away, though it is unclear whether the exhumation changed this.

Investigators also had a larger than usual pool of possible suspects, as the town’s population of 2,300 people surged over that weekend with the presence of 700 construction workers finishing a $34 million bark boiler at the Great Northern Paper Co. mill. Another 300 people were attending a statewide softball tournament in town.

The case also promoted, observers say, something of a division between early case investigators, who believe the homicide was committed by an out-of-towner, and those who suspect that the killer was closer to home.

Detective Joe Zamboni, who handled the case from 1986 to 2004, told the Bangor Daily News’ Doug Kesseli in 2005 that he believes that the person who killed McLain is “a very serious sociopath” and no longer a threat to anyone.

“When I looked at the case in the early ’80s, the investigation looked very seriously at people in the local area,” Zamboni said at the time. “By the time I retired, I felt very comfortable that the person responsible was not a local person.”

He has a specific suspect in mind.

“When you look at the crime, when you look at what happened, this is not a crime that was committed by a local teenager,” Zamboni said. “This is a crime committed by a very serious sociopath.”

Zamboni later added: “The person I believe is responsible for this is in a position that he’s not going to be able to do it again. I’m going to leave it at that … He’s no longer a threat to society.”

Occasional rumors about new suspects or persons of interest have come to light, and a federal judge recently chastised a convict in an unrelated crime for not helping police with the McLain homicide. Attorneys for the man, whom the judge said was a person of interest in the case, said that the man had cooperated fully. The man’s ex-wife said she had known for years that he had some knowledge of the crime but she expressed amazement at the judge’s admonition.

McLain and a group called “Justice For Joyce” scored something of a triumph when they raised enough money and got noted forensic experts Drs. Henry Lee and Michael Baden to exhume the body, over initial objections from state police and Maine ’s attorney general , in August 2008. That resulted, Lee and Baden said, in the discovery of new forensic evidence.

The casket and body were in remarkable condition, causing Baden to remark to Pamela McLain, “Your god has been good to you.”

Media attention and Pamela McLain’s pressuring have helped keep the case from fading away. After a segment of the TV show “Unsolved Mysteries” ran in February 1989, authorities received 49 tips that they followed up.

People Magazine wrote about the homicide and the involvement of Dr. Peter Cummings, who spent some of his childhood in Millinocket and was inspired by the McLain case to become a forensic neuropathologist.

The case took a sickening twist when someone defaced McLain’s grave in 2009, but investigation of that failed to result in arrests.

A somewhat antagonistic relationship between McLain and state police has developed over recent years, with McLain most recently enlisting U.S. Sen. Olympia Snowe to write a letter seeking FBI involvement in the case.

McLain has said she is still working to get the FBI more involved in the case, and Comcowich didn’t rule out further FBI involvement.

Follow BDN writer Nick Sambides Jr. on Twitter at @NickSam2BDN.