Vermont State Police are asking the public, businesses and hunters near a state university campus to review their surveillance systems after Honoree Fleming, a retired dean and professor who was married to best-selling author Ron Powers, was found shot to death on a rail trail this week.

Police said Friday night an autopsy showed that Fleming, 77, of Castleton, died from a gunshot wound to the head on Thursday afternoon. She was found on the Delaware & Hudson Rail Trail about a mile (1.61 kilometers) south of the Castleton campus of Vermont State University, which was closed.

“The campus will reopen Monday morning, providing a supportive environment for those who wish to come together,” Vermont State University spokesperson Sylvia Plumb said in an email Saturday. Monday events such as an admissions open house were canceled. Regular class schedules were expected to resume Tuesday.

A witness reported a possible suspect was northbound on the trail walking towards the campus after gunshots were heard, police said. The witness described a 5-foot-10-inch (1.78-meter) white male with short, dark-colored hair, last seen wearing a dark gray T-shirt and carrying a black backpack. State police said he is considered to be armed and dangerous and asked anyone who might have seen him to call them.

Maj. Dan Trudeau, head of the state police criminal division, said in a news conference Friday afternoon that some security camera footage from the area was reviewed, “which hasn’t been much of a help at this rate,” he said. “We’re still canvassing the area” and trying to reach people at their homes.

“It is early hunting season,” Trudeau said. “There’s hunters who may have game cameras in the woods.” He asked if they could check them.

She also was the wife of Powers, who co-wrote the book “Flags of Our Fathers,” about the men involved in the famous flag-raising during the 1945 Battle of Iwo Jima. A Pulitzer Prize winner in 1973 for criticism as a television-radio columnist, he also wrote a biography of Mark Twain and collaborated with the late U.S. Sen. Edward Kennedy on the politician’s memoir, “True Compass.” More recently, Powers wrote “No One Cares About Crazy People: The Chaos and Heartbreak of Mental Health in America,” about his sons’ battles with schizophrenia.

Fleming died days before what would have been the couple’s 45th wedding anniversary.

Her husband said she was walking on her favorite trail.

“There is an area-wide dragnet out for her killer,” Powers posted online Friday. “Police believe that it was random, but all possibilities remain open.”

He added, “Those of you who knew her know that she was beautifully named. I have never known a more sterling heart and soul than hers. She has taken far more than half my own heart and soul with her.”

McCormack reported from Concord, New Hampshire.