<P> The city became notorious worldwide for its rate of murders in the early 20th century , yet the courts failed to convict the killers . More than three - fourths of cases were not closed . Even when the police made arrests in cases where killers ' identities were known , jurors typically exonerated or acquitted them . A blend of gender - , race - , and class - based notions of justice trumped the rule of law , producing low homicide conviction rates during a period of soaring violence . </P>
what was the city of chicago known for at the turn of the 20th century
its rate of murders