
This episode covers the 1985 pipe bomb murders of Steve Christensen and Cathy Sheets, the investigation into Mark Hoffman, and the discovery of his forgeries.
Following Christensen's murder, another explosion occurred two hours later, killing Cathy Sheets, whose husband had a business connection to Christensen. Investigators found similarities between both bomb sites, including the use of a Mercury switch and gunpowder.
Mark Hoffman, a rare documents dealer, survived a third explosion the next day. Evidence suggested he was involved in the bombings, but he initially claimed to be a victim. Investigators uncovered inconsistencies in his story and evidence linking him to the bomb components.
Forensic analysis revealed Hoffman's history of forgery, leading to the conclusion that he murdered Christensen to cover up his fraudulent activities. Hoffman was ultimately convicted of second-degree murder and sentenced to life in prison.
Mark Hoffman murdered Steve Christensen and Cathy Sheets using pipe bombs to hide his forgery scheme, leading to his conviction.

This episode stands out for the following:
But who wanted to kill Steve Christensen and why?Forensic Files - Season 2, Episode 11 - Postal Mortem - Full Episode
It was real devastating to have your mother killed on your front doorstep.Forensic Files - Season 2, Episode 11 - Postal Mortem - Full Episode
What was entering in my mind was how soon are we gonna have another bombing?Forensic Files - Season 2, Episode 11 - Postal Mortem - Full Episode
Every single document that I looked at had been forged or manipulated in some way.Forensic Files - Season 2, Episode 11 - Postal Mortem - Full Episode
I think Mark is probably the most evil of people that I worked with.Forensic Files - Season 2, Episode 11 - Postal Mortem - Full Episode