A recent Forensic Files. Doctor wanted to *off* his nurse girlfriend, who was trying to end their relationship.
He took blood from one of his HIV+ patients - went to her home and injected her. The story was so preposterous that no-one believed her. But, a check of all phlebotomies charts and vials - proved her suspicions were correct. DNA was used to ID the strain of HIV and the donor patient.
Here’s the case file: Schmidt(doctor) & Trahan(nurse)
http://www.denverda.org/DNA_Documents/schmidt2000.PDF