Police say an autopsy ruled 34-year-old Christopher Darden's death an accident.
They say he suffocated due to environmental deprecation of oxygen and acute multi-drug intoxication, finding Methamphetamine, Tramadol, and Metaxalone in Darden's system.
Police say Darden went missing in mid-September after a family member reported his absence.
Later they say they found him at his home in Bowie, where he lived alone.
Police found him inside his bedroom closet, locked in a gun safe.
Police say they believe the safety panel was removed from the gun safe so someone could get into the safe and lock themselves inside.
Police are looking into some final details before they wrap up the investigation.
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