On the afternoon of June 4, Billy Daniel López García was making plans for the future. He took his girlfriend to a jewelry store and surprised her with a silver promise ring. He vowed to propose after her 20th birthday.

Before heading out to celebrate, the couple went to check on Mr. López García’s father at the family’s grocery store, Tienda Los Hermanos, which sells products from their native Guatemala.

They had been deeply unsettled by a string of violent robberies at other nearby Latino-owned businesses in Montgomery, Ala. — a restaurant worker shot in the hip after he took out the trash, an armed man terrifying customers at a Mexican ice cream store.

Only minutes before closing time, two armed men entered Tienda Los Hermanos, opened fire and killed Mr. López García, his father and a family friend.

“The United States is very dangerous,” Mr. López García’s girlfriend, Michelle Nambo Beltran, said. “It was Danny’s dream to be here,” she added, but “coming here cost him his life.”