When police officer John O'Keefe turns up dead, authorities arrest his girlfriend Karen for murder.

The murder trial of Karen Read begins and jurors hear testimony from witnesses at the scene where they found John O'Keefe's body; outside the courthouse, Turtleboy advocates for Karen's innocence.

As the trial continues, more details emerge about allegedly sloppy evidence collection, conflicting testimonies, manipulated video footage and baffling DNA results; Karen's team suggests a conspiracy and cover-up are at play.

As the trial winds down, experts attempt to recreate John's death, the defense brings in one final witness and closing arguments grip the nation; Karen, emotional after a long haul, anxiously awaits her fate; the jury returns with an unexpected note.