Jung Yun’s first book began with one single image, the debut novelist recalls. “There was a scene in which a man looks out his window and he sees his elderly mother walking toward his house, naked,’’ Yun said. “The idea just sat around for years and years. I put it away in a mental drawer.’’

It wasn’t until she became fascinated by a horrifying nearby crime — the triple murder of a mother and two daughters in Connecticut in 2007 — that Yun began to expand the scene into a book. “I read everything I could, watched everything, listened to everything,’’ Yun said. “That event started spiraling out into some questions, like, what if a similar crime happened to another kind of family? That was the connection between that single random image and the novel that it eventually became.’’

The result was “Shelter,’’ Yun’s debut novel, in which a Korean-American family is devastated and disrupted by a terrible crime.

Born in Korea, Yun grew up in Fargo, N.D., where her father opened a martial arts studio and her mother owned a retirement home. “We were the only diversity for miles,’’ Yun recalled. Her family’s ethnic isolation helped make her a fiction writer, Yun said. “I think because I knew from a young age that I was different from the other kids at school, and that my family was different from the other families in town, I got accustomed to being very observational. I got in that habit of looking at people, not quite as characters, but seeing what characterized their interactions with each other.’’

After a New York-based career in nonprofit work, Yun’s move to Western Massachusetts to pursue an MFA in creative writing was, she said, “exactly what I needed.’’ She is, she laughed, “one of those who just stayed.’’

Yun will read from her book at a launch party at 7 p.m. Tuesday, at Amherst Books, 8 Main St., Amherst.

Kate Tuttle, a writer and editor, can be reached at kate.tuttle@gmail.com.