What is one example of how the Locard Exchange Principle is used in a crime scene?

An example of the Locard Exchange Principle in a crime is if someone is strangled to death and you find a suspect with the victim's skin cells under his nails. The case is then solved. The Locard Exchange Principle helped with this case because it shows that during the contact of the victim and the murderer (during contact of two surfaces), the skin cells were left on the murderer's nails (transfer of evidence is created).