Guatemala City is one of the most dangerous places in the world. Less than 15 out of 5,000 murders result in a conviction. A culture of political repression and intimidation has left people reluctant to trust the judiciary. But - with the help of C.S.I training - an elite group of officers hope to change things. We follow the special homicide task force as they process up to 30 killings a night. We also hear from the killers and victims, who risk all to seek justice.