Neighbors knew something was wrong in that squat green house when a young woman's screams pierced the quiet of their neighborhood in Chalchuapa, a small town about 80 kilometers (50 miles) from San Salvador, this nation's capital, Reuters reported.

Jacquelinne Palomo Lima, 26, and her mother had been lured to the windowless dwelling by the man who lived there—51-year-old former policeman Hugo Osorio—who had promised them information about Palomo's missing brother, Alexis, a family member told Reuters.

Neighbors called police when they heard Palomo's screams on the night of May 7 as she fled the home only to be overtaken by Osorio, who allegedly hit her in the head with a metal pipe and dragged her back inside. By the time authorities arrived, the bodies of Palomo, her brother and her mother were found, along with another 14 corpses initially discovered in a mass grave behind the home, Justice and Security Minister Gustavo Villatoro told journalists on May 20.

El Salvador has long had one of the highest rates of violent crime in the world. But even in this country inured to mayhem, the Osorio case has shocked the public. Local media have dubbed the dwelling the "House of Horrors."

Osorio was charged on May 12 on two counts of femicide, a term used for killings that deliberately target women; prosecutors later added two counts of homicide. At least nine other people have also been charged with aggravated homicide and femicide in connection with the slayings.

According to details of Osorio's alleged confession, he purportedly admitted targeting mostly poor women and girls, luring them to his home with the promise of jobs or help in migrating to the United States. Villatoro, the security minister, called him a "psychopath."

But Osorio's law enforcement background, the large number of potential accomplices, and the dearth of public information about the case have some Salvadorans unsure of what to believe.