Murder in Texas (1981)

Story of Texas heiress Joan Robinson, who married plastic surgeon John Hill. Her father, Ash, is suspicious of Hill, thinking that he married Joan for money, which he used to buy a house and indulges in some odd hobbies. He eventually has an affair with a woman named Ann Kurth. Eventually Ash threatens John with him losing custody of his son unless he makes full restitution to Joan. One day, Joan gets sick and dies. John somehow doesn't allow an autopsy to be done. Ash thinks it's strange, and thinks John killed Joan and sets out to prove it. John eventually marries Ann and she can't help but find his behavior strange.