It was evening in Ajalpan when two young pollsters from Mexico's capital ducked into a store to conduct a survey about tortilla consumption.

Someone didn't like it, and they called the cops. "There are suspicious people on Guerrero Street. They're asking a lot of questions," the anonymous tipster reported, Police Chief Juan Manuel Gonzalez said.

An hour and a half later, about 8 p.m. Monday, brothers Jose and David Copado Molina lay dead, mistaken for criminals and beaten to death by a mob of townspeople frightened by both the gang violence plaguing much of Mexico and recent tales of alleged child abductions.

Rumors spread recently in this part of southeastern Puebla state by word-of-mouth and on social media: Someone is kidnapping children to snatch their organs, folks said. Many grew furious with the mayor for purportedly failing to ensure public safety, though authorities say they have not received a single complaint of an abduction.

Local media in Puebla say there have been as many as 10 incidents of vigilantism against suspected criminals in the last year resulting in three deaths, but there are no official accounts to corroborate that. Such cases rarely make it to the courts.

The churning emotions displayed in Ajalpan underline the feelings of insecurity and lack of trust in authorities to keep people safe in Mexico, where many thousands of people have disappeared in recent years.

"The phenomenon of lynching or people taking the law into their own hands, and the frequency with which it has presented itself in the state of Puebla, is evidence of the fragile rule of law," the National Human Rights Commission said.

The bloodshed in Ajalpan shocked people across Mexico, in part because it quickly became clear the two victims were only young pollsters doing their job, but the mob killed them anyway.

As police took Jose and David to City Hall to try to protect them, angry people surrounded the building. Initially deemed suspicious for asking a lot of questions, the Copados were now accused of molesting a local girl.

She was brought to City Hall along with her parents, but said she had never even seen the brothers before. The parents went outside and tried to calm the mob.

"'You're letting yourselves be fooled,' they told them," municipal secretary Juan Guzman recalled.

The crowd, by now some 2,000 strong, began to pelt the building with rocks.

Gonzalez, the police chief, tried to move the Copados to safety on the second floor. But people broke inside and began trashing the place as the brothers looked on in shock.

"The last thing I remember was the two brothers holding onto each other's hands," Gonzalez said.

The mob dragged them outside and beat them to death. One young man, his face obscured by a motorcycle helmet, splashed the bodies with gasoline and set them on fire.

Jeannette Rodriguez was attending a dance class at the building and saw the violence. She said she didn't join in, but shared the frustration voiced by the crowd.

"That's not the method we should use," she said during a community meeting a few days later to discuss the killings. "But something has to be done."

A group of mothers gathered around her agreed. Each one had a tale of violence and woe that supposedly happened in the town.

"There are disappearances. There are thefts of children. There are kidnappings. There is a girl who turned up eight days ago with her organs missing," said Gabriela Vazquez, president of a parents' committee. "The authorities say no, but all this is happening. It's true."

Vazquez said she is also a police officer. On her legs were bandages — the result of injuries suffered trying to defend the brothers, she said.

A day before the killings, a Facebook group called "Ajalpan Actual," which has nearly 5,000 followers, published an item about a girl who had supposedly gone missing.

Days earlier another Facebook page called "Ajalpan" carried the following message: "In the last two weeks there have been reports of the disappearance of two girls approximately 15 years of age. Recommend reporting suspicious vehicles and/or people. Please, may we not remain silent and if we see something, act, report cars and license plates etc. We need to take care of ourselves."

Guzman, Ajalpan's municipal secretary, told The Associated Press that there has been no formal complaint or evidence matching the Facebook reports.

"People on social media are committing very irresponsible acts by spreading false information," he said.

Vazquez, the mother and police officer, said: "The town will live with remorse knowing what it has done."