Henry Duncan was tried in a California court for robbery and murder after his supervisor was found dead in a small office at Duncan’s workplace. During trial, evidence was introduced to show that Duncan was present at the crime scene, including his palm prints, fingerprint, and shoe print that were found at the scene. The jury also heard testimony from a criminologist for the Serology Section of the Los Angeles Police Department regarding blood found at the crime scene. The criminologist explained that three blood samples lifted from the scene were inconsistent with the blood of both Duncan and his supervisor.
The defense theory proffered by Duncan’s counsel was that someone other than Duncan committed the murder. At trial the attorney brought out the fact that the criminologist could have distinguished Duncan’s blood with blood found at the crime scene if he had had access to a sample of Duncan’s blood. However, Duncan’s blood was never given to the criminologist to test, a fact which the prosecutor turned to his advantage in closing argument. Duncan’s attorney offered no evidence that anyone other than Duncan was present at the crime scene or that anyone other than Duncan was the actual killer.
