Two for the Price of One
Most commonly, this occurs in patients that receive bone marrow transplants. Although it's extremely rare, this phenomenon has happened enough that scientists named it “chimerism”. Named after the creature of Greek mythology that’s composed of a goat, a lion, and various other reptilian appendages, chimerism is when an individual has two sets of DNA. This would have been perfectly fine if the chimera wasn’t a member of a police department, and the DNA he took on didn’t come from a criminal living in Ireland…