I recall when I first heard about Terri Shiavo. I thought there is no way anyone will allow her to starve to death. They did. I still think the husband knew of the Hillsdale, Michigan case where a husband said his wife fell off a horse and struck her head and died. It was found later that he had administered a muscle relaxer that prevented all movement. The drug would dissipate in the system. But a California pathologist found a way to test for the metabolites. Yup, the husband is serving life in Michigan prison. I always thought the Shiavo husband knew of the drug, being medically trained.
Found it if anyone is interested: David Davis, Hillsdale, Michigan, killed Shannon Mohr with horse tranq. He died while still in prison.