The Garbage That Gave Him Away: How Discarded DNA Can Solve a Crime

Sometimes detectives know exactly who they want to investigate but lack the evidence needed to prove it. DNA may already exist from a crime scene, yet investigators still need something belonging to the suspect for comparison. That is when an ordinary coffee cup, cigarette butt, drinking straw, or piece of trash can become extraordinarily important. Once an object has been abandoned, investigators may sometimes collect it and test biological material left behind. This episode examines how discarded DNA can transform suspicion into evidence—and why the technique is more complicated than simply pulling something from a garbage can.