A welfare check for 70-year-old Harold Thompson led to a 17-hour standoff at a home on Old Mills Road in Tecumseh, Oklahoma, on Monday, October 13, 2025. Family had reported Thompson missing; when Pottawatomie County Sheriff’s deputies arrived at the house he shared with his son, the son ran inside and barricaded himself and displayed a firearm through a window. Deputies had previously responded to the home in May after the son allegedly threatened suicide and reportedly told deputies he believed his father was an imposter; the son was taken for a mental health evaluation then.

After a tactical team deployed tear gas and entered the residence, deputies found Harold Thompson deceased inside. The preliminary medical examiner’s findings reported two gunshot wounds, one to the head and one to the shoulder, both from behind, and the body’s condition indicated he had been dead for several days. Harold Thompson’s son, John Thompson, and a woman who was inside the home, Katelynn Cowett, were arrested and charged with first-degree murder; the Oklahoma State Bureau of Investigation is assisting the homicide inquiry.

If anyone knew Harold Thompson, the household dynamics, or observed activity on Old Mills Road before October 13, what can be shared with investigators?