Ms. Alawadi and her husband moved to the United States from Saudi Arabia in 1995 after fleeing Iraq during the first gulf war. They then had five children, and for the most part, Mr. Alhimidi said, their neighbors here made them feel welcome.

Still, even before this month, he was already familiar with the kind of language he says was on the notes left at his house.

“Some neighbors, I say ‘hi’ to them, and they just turn away,” Mr. Alhimidi said in Arabic, with his son Mohammed translating. “More than 95 percent of the time, I feel welcome. But once in a while, people shout at you. They shout ‘terrorist,’ or ‘go back to your country.’ ”

Most people in town lamented Ms. Alawadi’s killing as a tragedy. Janet Ilko, a middle school teacher, said the news had come as a shock to students.

“It was upsetting to everyone,” Ms. Ilko, 47, said. “Our community is very close-knit. Our students get along very well. People have been here a long time.”

But tension between the newcomers from the Middle East and some of the town’s other residents was also readily apparent on Main Street, even this week. One woman, 30, who was at a park with her children and refused to give her name, called the city’s Iraqi residents “territorial,” adding, “maybe because we are at war with them.” She said her own background was Mexican, though she had grown up in Southern California.