Why would someone kill a retired academic in broad daylight on a popular walking trail in the town of Castleton, Vt.? Six months after Honoree Fleming was shot in the head along the D&H Rail Trail on Oct. 5, police are still trying to answer that question.

“It’s bizarre,” Castleton Police Chief Peter Mantello said of the 77-year-old woman’s fatal shooting. “Everybody’s kind of dumbfounded with it.”

It was the first homicide case the university town had seen since 2014, when local farmer Stephen Pelletier shot and slashed his daughter’s boyfriend.

Fleming retired in 2012 as dean of education at what was then called Castleton State College, now part of the Vermont State University system. She had no known enemies, Mantello said, and appeared to have been spending much of her time working on a scientific paper.

Police said there have been no major leads since they released a sketch of “a person of interest” in the case last October. The person, described as a white man in his 20s who had been reportedly acting strange near the area where Fleming was killed, has not been found, said Maj. Dan Trudeau, commander of Vermont State Police’s criminal division, the lead investigating body.

The man was likely Fleming’s attacker, Trudeau told VtDigger, adding that it has been difficult for police to definitively label him the suspect without knowing his identity or having spoken to him.

“Nobody witnessed the killing that we’re aware of — other than the killer,” Trudeau said.

Castleton residents’ offer of a $25,000 reward for information leading to the killer’s arrest and prosecution has also not moved the needle, though Trudeau said it is common for state police to still get one or two tips a week on the case.

He said troopers continue to actively investigate Fleming’s shooting. He underscored that it is not classified as a “cold case,” in which leads have dried up.

“The detectives are going through a lot of new (tips) that come in,” Trudeau said, “and all the old ones, they’ll go back through them a number of times.”

While police aren’t reporting any breakthroughs, he said, they typically sift through investigative material such as DNA evidence, digital files and cellphone records in similar cases.

He declined to discuss specifically what steps they’ve taken in the Fleming case, citing the need to maintain the investigation’s integrity.

“A lot of what you do in any case is ruling out people as much as you are trying to rule people in,” Trudeau said. “Sometimes it just takes a long time to put it together.”

Rutland County State’s Attorney Ian Sullivan declined to comment on the investigation, apart from saying that police have stayed in close touch with his office.

Police and prosecutors typically work closely even before criminal charges are filed, since investigators might need to use court-sanctioned tools such as search warrants and inquests.

“We’re very much working hard to bring this case to justice,” Sullivan said.

Fleming’s widower, Ron Powers, said his priority right now is the couple’s 42-year-old son, Dean, who has been diagnosed with schizophrenia and lives with him.

Fleming and Powers lost their other son, Kevin, by suicide in 2005.

“I feel that Honoree is dead and nothing else matters except Dean,” Powers, 82, said in an email. “Aside from my concern that the killer remains a public menace, I really don’t care whether he’s caught or not. Honoree is dead.”

Fleming and Powers, a Pulitzer Prize-winning author, had been married for 39 years. Powers said his wife’s killing, and the way it was carried out, have torn him apart like nothing else has.

“The trauma and grief have aged me ten years,” he said. “I’ve lost my sense of balance and much memory. It’s hell.”

Law enforcement officials believe someone out there has crucial information about Fleming’s killing that can help solve the case.

“I’m always hopeful that people who have, for whatever reason, not come forward yet will look into their conscience and decide that they need to share what they know with law enforcement,” said Sullivan, the state’s attorney.