A man in the United States' Oklahoma has killed a woman neighbour and cut out her heart before cooking it with potatoes.

While obtaining a search warrant, an agent with the Oklahoma State Bureau of Investigation told a judge that Lawrence Paul Anderson killed his neighbour, Andrea Lynn Blankenship, at her home in Chickasha, about 40 miles southwest of Oklahoma City, and cut her heart out before cooking it and serving it "with potatoes to feed to his family to release the demons."