A Lafayette hashtag trended on Twitter in the hours after smartphone footage of Mr. Pellerin’s death surfaced. But it didn’t take long for fires in Wisconsin, the crisscrossing paths of back-to-back hurricanes barreling for Louisiana’s coast and the theater of the Republican National Convention to shove Lafayette’s uproar to the margins of national consciousness.

The larger protests that packed streets soon dissipated to scattered bands of demonstrators. On Friday, hundreds of people joined a march organized by student athletes at the University of Louisiana at Lafayette, mirroring an athlete demonstration in Baton Rouge at Louisiana State University.

Mr. Pellerin was shot at a gas station on a busy highway that physically divides Lafayette, near a working-class neighborhood dotted with modest family homes. On one corner, a memorial took root with balloons and ribbons, a small and solitary marker reminding those driving by of what had happened just over a week ago.

For some, a sense of weariness had set in.

“You can’t keep up with the stories because they’re happening too fast,” Tameka Therman, 37, said of the violent encounters between African-Americans and the police that have captured widespread attention.

Sylvia Richard, a retired schoolteacher, said she was disheartened as she saw the attention being paid to Mr. Pellerin’s death pale in comparison to other cases around the country.

“I know we’re a small town compared to most, but I don’t think it’s receiving enough attention,” Ms. Richard said. “What happened here mirrors what happened in Wisconsin, but nobody’s really paying attention to it.”

Mr. Pellerin’s family has felt their pain overshadowed, said Ronald Haley, their lawyer, noting that New Orleans Saints players had taped Jacob Blake’s name to their helmets.

“That’s great,” Mr. Haley said of the gesture. “But, man, we have somebody dead two hours away in Lafayette. We need to get them to get behind this family as well.”

Christiaan Mader and Will Wright reported from Lafayette, and Rick Rojas from Beaumont, Texas.