Acclaimed US drama about a Miami police forensics expert who kills those he believes have escaped justice. Starring Michael C. Hall. Dexter was orphaned at the age of three after the murder of his mother, an incident which appears to have implanted in him a fierce desire to punish those who commit criminal acts. While avoiding suspicion with a genial and helpful professional facade by day, when off-duty Dexter remorselessly hunts down those he believes have escaped the justice of the law and takes his vengeance.