When Afrikka Hardy was strangled in 2014 it seemed completely random, but it wasn’t. It was part of a pattern. Four years earlier, reporter Thomas Hargrove had created an algorithm to detect serial killers and flagged Gary, Indiana as the site of an unusual number of strangulations. But when Hargrove reached out to warn local police, he was ignored -- until Afrikka Hardy was murdered, and those cold cases suddenly didn’t look so cold. Algorithm follows the investigation into Afrikka’s murder, exposing the warnings that police ignored, and uncovering more than anyone expected -- that a...