On Father’s Day, 2005, Robert Farquharson crashed his car into a dam. He survived, but his three children who were in the car with him didn’t. At first it seemed like a tragic accident. But quickly, it turned into a murder investigation.   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. See omnystudio.com/listener for privacy information.