
This episode covers the murder of Julie Williams, the attempted murder of Diane Harry, and the investigation into Lewis Harry and Roy Fitzpatrick.
Julie Williams, an employee at Transamerica Title Insurance in Tempe, Arizona, fell ill after drinking from a water cooler. Investigators discovered that the water was poisoned with cyanide, leading to Julie's death and raising alarms about the safety of the office.
Police investigated the source of the cyanide and found that it had been placed in the office coffee pot and water cooler. Diane Harry, another employee, revealed that she might have been the intended target, as her husband, Lewis Harry, had a motive tied to a potential affair.
Lewis Harry was implicated after evidence linked him to the purchase of cyanide and threatening letters sent to himself. The investigation revealed a manufacturing flaw in the envelopes used for the letters, which helped identify him as the sender.
Ultimately, Lewis Harry was convicted of first-degree murder and attempted murder, receiving a life sentence. The episode highlights the complexities of the case and the tragic consequences of his actions.
A murder investigation reveals cyanide poisoning linked to a love triangle and a flawed envelope.

This episode stands out for the following:
This proved that lewis harry sent himself at least one of the threatening letters.Forensic Files Season 11, Episode 24 - Water Hazard - Full Episode
She was an innocent victim of a marriage gone horribly wrong.Forensic Files Season 11, Episode 24 - Water Hazard - Full Episode
I still can't forgive him.Forensic Files Season 11, Episode 24 - Water Hazard - Full Episode