Mark Diffin, 33, of Tulsa, Oklahoma, was found dead inside his home on February 5, 2011, after what authorities described as a violent confrontation that turned his residence into the scene of his death. Neighbors and family were left to piece together the hours before he was found, with few public details about the immediate circumstances inside the house.

Investigators focused on people in Diffin’s close circle and identified a woman who knew him, Michelle Millikin, as the primary suspect. Prosecutors filed charges in connection with the killing, but multiple mental health evaluations later concluded Millikin was not competent to stand trial. The court dismissed the criminal charges and she was committed to the Oklahoma Forensic Center. Law enforcement records classify the homicide as solved and no other suspects have been publicly identified.

If anyone knew Mark, his routines, or saw activity around his home in early February 2011, please share what might help clarify his final hours.