The Importance of DNA in Forensics

In 1991 a waitress in Carson City Nevada is serving a table of three there's a teenage girl and an adult couple who the waitress describes later as quote unkempt. The girl keeps dropping her silverware to the ground like over and over and it's happening so much of the waitress thinks it might be on purpose for attention. After the group leaves the restaurant the waitress picks up the girl's plate and under the plate there's a note that says help me call the police holy shit yeah I don't recommend listening to it"