In the story of Robert Farquharson, there's one thing that’s hardest to understand: his behaviour in the minutes and hours after the crash.

Because on that night, his actions seemed so far outside normal behaviour for a father that the police, the media and the general public all came to the conclusion that he must have murdered his three sons.

But is that true? Or is there some other explanation for his unsettling behaviour that night?

For exclusive content and additional reporting on the case, available to subscribers of The Age and The Sydney Morning Herald, visit theage.com.au/trialbywater or smh.com.au/trialbywater. Subscribe now to access the special Good Weekend investigation, which features never-before-seen 3D models recreating key scientific evidence, video, audio and other interviews.

The original version of this episode included a re-enactment of parts of Robert Farquharson's formal police interview. We decided to do the re-enactment because of a legal threat from Victoria Police that we would be in breach of a 2009 law, and potentially liable for imprisonment, if we included the audio of the original interview. But since then we’ve clarified that parliament never intended the law to apply to old recordings, so we’ve replaced that re-enactment with the actual interview of Robert Farquharson.