“He was savagely beaten with truncheons, fists and kicks until he fell to the ground, but the punishment continued,” said a criminal complaint filed on behalf of Sofiane Naoufel El Allaki, a 21-year-old deliveryman for Amazon, by a Paris human rights lawyer, Samim Bolaky.

“The screams of Mr. El Allaki penetrated the whole neighborhood,” the complaint said.

“This is not about confrontation,” Mr. Bolaky said. “This is not urban violence. The streets are deserted. They didn’t even ask him for his release form. He didn’t resist at all.”

The police in the Essone department, where the incident took place, did not respond to a specific inquiry about Mr. El Allaki’s claims. Mr. El Allaki’s case is one of several involving police violence being investigated by prosecutors.

Mr. Esmili, the sociologist, warned that the way the authorities were enforcing the lockdown was only reinforcing the worst expectations of many in France’s poorest areas.

“Look, the state is completely ignoring how people live in these neighborhoods,” he said. “Its only response to them is an excess of authoritarianism. And the people are beginning to understand, the only response is police force.”