Anatomy of Murder The Man Beneath the Floorboards (Mark Koster)
Jan 20, 2026
In a gripping discussion, Ben Smith, Sac County's attorney, shares the harrowing tale of Mark Koster, who was declared dead long before his remains were discovered mummified in his basement. Smith illustrates how a mysterious note and a neighbor's tip about a tall man with a Pomeranian led to uncovering the truth. As they dive into forensic details, the chilling confrontation with suspect John Green reveals a tangled narrative of self-defense and concealed crime, culminating in a conviction that left the community shaken.
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Body Hidden In Plain Sight
- Ben Smith and investigators found a mummified body in a cluttered basement hidden under blankets and kitty litter.
- The homeowner discovered the remains while remodeling and immediately called 911.
How Kitty Litter Preserved The Remains
- Kitty litter's silica crystals desiccated the remains and preserved the body, masking odors.
- The medical examiner ruled homicide by strangulation based on a broken hyoid bone.
Declared Dead Before Body Found
- Mark Koster was declared legally dead in October 2011 after his family petitioned following months of no contact.
- The declaration preceded the 2012 discovery of his body buried in his own home's basement.