Insulin as a murder weapon
February 2, 2012, 2:33 am
Murder by insulin: suspected, purported and proven — a review. Marks V. Drug Test Analysis 2009;1:162-176.
With the recent death following an unexpected hypoglycemic episode of a fifth patient at Stepping Hill Hospital in Greater Manchester (U.K.), this classic article on the forensic pathology involving insulin as a murder weapon has become even more timely. Dr. Marks is one of the foremost experts and expert witnesses in the field, having testified at the Claus von Bülow trial, among many others.
Marks points out that:
[Insulin] is an inefficient and ineffective weapon, largely because of the length of time it takes to cause death and the ease with which it can be diagnosed and treated.
Through personal knowledge and review of both medical and lay literature, the author provides summaries of 66 cases involving persons who were alleged or known to have been poisoned by insulin. He makes the following points:
- Blood glucose measured after death is unreliable as an indication as to whether the victim actually died of hypoglycemia.
- In general, glucose disappears from blood after death.
- However, post-mortem blood collected from the right heart can be artifactually elevated, because of breakdown of liver glycogen.
- B-cells of the pancreatic islets of Langerhans produce proinsulin, which is broken down after release into equal amounts of insulin itself and C-peptide.
- Surreptitious insulin administration will cause elevated insulin levels but low or absent C-peptide.
- The differential diagnosis of hypoglycemia with extremely elevated insulin and C-peptide levels include insulinoma and poisoning with drugs such as sulfonylureas that stimulate insulin release.
- Other causes of life-threatening hypoglycemia include sepsis and alcohol-induced hypoglycemia.
By the way, the Claus von Bülow affair is case number 32 summarized in this paper. It is discussed in much more detail in Dr. Marks’ book Insulin Murders: True Life Cases. Von Bülow was initially convicted for using insulin in the attempted murder of his wife Sunny, but the conviction was overturned during a second trial. This episode was the subject of the movie Reversal of Fortune, that had this classic scene between von Bülow (Jeremy Irons) and one of his defense lawyers Alan Dershowitz (Ron Silver):
This scene was later referenced in The Lion King — an animation in which the villain Scar was voiced by Jeremy Irons.