Diabolical takes an in-depth look at multiple murderers through a psychological prism. Using re-enactments of key moments, as well as archival footage and eyewitness interviews, this dramatic series grapples with the most pressing question of all - could these individuals have been stopped before they killed?
David Messenger brutally murders his pregnant wife Heather in front of their 5-year-old son. The crime comes as a shock. Did he kill his wife in self-defense, did he fall victim to mental illness, or was something even more disturbing going on?