Hundreds of federal agents stormed a town on the Mexican capital's southern outskirts on Wednesday night, breaking down doors in an effort to collar the leaders of a mob that burned two police officers to death in the area.
A long convoy of government vehicles sped into San Juan Ixtayopan just before sunset, carrying 600 federal operatives as well as hundreds of city police officers who sealed off streets, then went home to home to look for suspects, said Elizabeth Juarez, a spokeswoman for the federal attorney general's office.
Without firing a shot, authorities captured at least 20 people, and the swarm of police forced dozens of others to run to their houses and shut off the lights in an effort to keep from attracting attention.
After two and a half hours, most of the authorities involved in the raid left the area, saying that three of those captured were directly involved in organizing the mob killings and that at least one would be accused of starting the fires that killed the federal agents.
Throughout the day, all major television networks replayed chilling images of a young man, his face bloody and swollen, struggling to tell a television reporter that he is an undercover federal agent. A short time later, a mob burned him and another officer alive on camera.
The horrific footage from the killings on Tuesday night put a spotlight on growing vigilante justice in Mexico, where police are viewed as inept at best and corrupt at worst and where many people say they must take security into their own hands as crime soars.
The officers' deaths came amid rumors that children had been kidnapped from an elementary school in San Juan Ixtayopan, a neighborhood of 35,000. When people saw three men taking photos and staking out the school, they took action.
One after another, residents set off dozens of crude, rooftop bullhorn alarms that serve as a backup security measure in some poor districts. Neighbors poured into the streets, where they cornered and then beat the men. Onlookers cheered and shouted obscenities as they were splattered with blood.
Reporters arrived, and the assailants pushed the victims before TV cameras so they could be interviewed. Barely conscious and struggling to talk, they nodded and gave one-word answers when asked if they were federal agents.
As television helicopters hovered overhead, police began to arrive. One agent was rescued, carried away unconscious by his arms and legs. His condition worsened on Wednesday and he was in critical condition by evening, authorities said.
The other two officers were soaked with gasoline and set ablaze, their charred bodies left bleeding in the street as dozens of people milled around.
Mexico City Police Chief Marcelo Ebrard said local police were on the scene immediately but couldn't control the crowd until hundreds of reinforcements arrived.
"The problem was that there were more than 2,000 people, angry, out of control, at night," he said.
Federal police director Jose Luis Figueroa said the three plainclothes agents had been sent to the neighborhood to investigate drug dealing near the school.
There appeared to be little remorse in San Juan Ixtayopan, a picturesque community tucked into pine-covered hills at the foot of a snowcapped volcano.
Before Wednesday night's raid, people milled about in the central plaza, discussing the bloodshed as vendors loudly hawked tabloid newspapers carrying photos of the victims and boldfaced headlines that screamed "Lynched."