SOUTHWEST HARBOR – The sun sparkled Thursday afternoon on the lobster boats bobbing in the harbor and shone on the residents who bustled around the shops of the picturesque downtown, but the bucolic scene masked a vein of unease running through the community.

Retired math professor Jacqueline “Jilly” Evans, 83, died Jan. 22 after being attacked in her home on Alder Lane in the sleepy village of Manset by an unknown assailant or assailants. State police have not released many details of the homicide investigation, and residents are filling in some of the blanks with rumors – and fears.

“We don’t have things like that happen around here,” said Emma Cunningham of Somesville. “It’s frightening. I think a lot of people were locking their doors after that happened. Like locking the barn door after the horse escaped.”

Cunningham, an 87-year-old who carries a cane, was having her blood pressure checked before starting a cardiopulmonary rehabilitation class at the Harbor House, a nonprofit community center that provides services for the elderly. She said that she hasn’t let the tragedy of the elderly professor who lived a few miles down the road dominate her life.

“It seems that it is quite far removed from my life, something like that,” she said. “I hope.”

Southwest Harbor is the largest town on Mount Desert Island’s “Quietside,” counting nearly 2,000 year-round residents in the last census. Though its population triples in summer, during the off-season many stores are shuttered and the town feels more like the kind of village where everyone knows everyone else.

“I think people are concerned that this homicide hasn’t been solved,” said Peter Homer, Harbor House’s executive director. “It’s creating a scare. … This has always been a community of open doors and unlocked homes. I think people are thinking twice about that.”

One constant current heard around town is that such serious crimes just don’t happen in places as small and quiet as Southwest Harbor.

In fact, Evans’ murder is the town’s first since boatyard worker Stephen Lockhart killed his wife, Andrea, in December 1998 and hid her body in a makeshift fiberglass coffin. Lockhart is serving a 47-year prison sentence for the grisly crime.

Between 20 and 25 homicides occur in the state in an average year, according to the state police Web site. About 90 percent of those are solved.

Local officials encouraged nervous residents to be careful as they go about their business.

“Something I have always said to my kids is that you have to be aware of what’s going on around you, know who is around you, those kinds of things,” said Ken Minier, town manager. “You just never know. You never know.”

Some residents have said that they think Evans’ solitary lifestyle and trusting ways might have played a role in her fate.

“She lived alone there, and that is what I think had made her so vulnerable,” her friend Linda Shultz said two weeks ago. “She was like the rest of us – she kept her doors open and lived a simple life.”

Bass Harbor resident Anne Geary, a nurse who was helping to perform checkups on the older adult crew at the Harbor House, said that Evans’ murder was very worrisome.

“One doesn’t like to hear about people who live alone being attacked,” she said. “It was a very upsetting event.”

Minier echoed the refrain that townspeople who had felt safe before Evans’ murder may be changing their ways, and that everyone is hoping for an arrest to put an end to the rumors and fears.

“I have a feeling that there are a lot fewer people who leave their homes unlocked than before, and I don’t say that to be funny,” the town manager said. “I hope they find the person. I hope this goes to some conclusion. … I think that would probably help the people in town a lot.”