Antonio Zuñiga's life changed when he went for a walk on Dec. 12, 2005. As he crossed a busy Mexico City avenue, two burly cops grabbed him from behind and shoved him into a patrol car.
So began a nightmarish journey into Mexico's legal system that seems lifted from the pages of Franz Kafka. For nearly two days, the street vendor was held incommunicado and not told why he was arrested. His questions met with hostile stares from detectives, who would say "You know what you did." He says in an interview that he only learned of the charges after walking into a holding cell and being asked by a prisoner: "Are you the guy accused of murder?"
Mr. Zuñiga, then 26, was charged in the shooting death of a gang member from his neighborhood. Ballistic tests showed Mr. Zuñiga hadn't fired a gun. Dozens of witnesses saw him working at his market stall during the time of the murder, which took place several miles away. And he had never met the victim. Still, he was found guilty by a judge at trial and sentenced to 20 years in prison.
Mr. Zuñiga's case is not unusual in Mexico. Crooked cops regularly solve cases by grabbing the first person they find, often along with a cooked-up story from someone claiming to be an eyewitness. Prosecutors and judges play along, eager to calm a growing public outcry over high crime rates and rising violence from Mexico's war on illicit drug gangs. In practice, suspects are often presumed guilty. More than 85% of those charged with a crime are sentenced, according to Mexico's top think tank, the Center for Investigation and Development, or CIDE.Mr. Zuñiga's story has a twist. His plight attracted the attention of Roberto Hernández and Layda Negrete, a married pair of lawyers who are also graduate students at the University of California at Berkeley. The couple took on his case, won a retrial, and in a stroke of luck, convinced a Mexican official to let them film the ensuing trial, which lasted for more than a year.
The result is a 90-minute documentary called "Presumed Guilty" that offers a rare—and chilling—glimpse of Mexico's dysfunctional legal system.