Near Southwestern Law School in the Koreatown neighborhood of Los Angeles, a grass strip between the sidewalk and curb is fenced off with green plastic to keep homeless people away. But around the corner is an encampment with a few dozen tents.

“I think they care more about animals than us,” said Lucrecia Macias, a nurse who lived in a house in Palmdale before cancer wiped her out financially and led her to the streets. “They’re making parks for dogs but they’re not building housing for us.”

Lynell Cain, who also lives in a tent at the encampment, said the community response had grown worse in recent months. “They’ll kick you out of stores,” he said. “They won’t even let you into laundromats to wash your clothes. The bus driver won’t pull over.”

Josh Rubenstein, a spokesman for the Los Angeles Police Department , called homelessness “the crisis of our generation.” Despite high-profile violent attacks such as a beating death on Skid Row, an intentional fire at an encampment in Eagle Rock, and an arson attack on Skid Row in which a homeless musician died, Mr. Rubenstein said, the authorities had not seen an increase in violence toward the homeless attributed to the community backlash. (Some cases have involved violence among homeless people, and in others, such as the Eagle Rock case, the motive is unclear.)

Still, he acknowledged a growing frustration among residents. “There are strong, strong feelings on all sides of this issue,” he said.

Part of that exasperation, at least in Los Angeles, comes from two publicly approved actions in recent years — a sales tax increase and a bond measure — to spend billions of dollars on the problem of homelessness, which officials pledged would mitigate the issue. But thickets of regulations in California stand in the way of a quick housing fix.

“I think those of us in the service-provider community always knew we weren’t going to solve the problem,” said Mr. Maceri of the People Concern. “But I think the expectation was we were going to make a significant dent. So on the one hand, the message is we have all these resources to quote-unquote solve this problem. And what the general public sees is, it’s not getting solved, it’s not getting better, it’s getting worse.”