Forensic science has come a long way since the late 1960's and almost certainly had the Zodiac committed his crimes today he would be safely locked up behind bars, but there still may be a chance with DNA and not by the conventional method of entering the suspects data into CODIS ( Combined DNA Index System ) to search for a match.
This new system works by taking the Y chromosome from a suspects DNA and instead of searching for a direct match, which of course is wholly reliant on the suspect being in the database, this system removes that need. In other words the suspect does not have to have committed a prior offence to be matched.
It works by creating a database of thousands of different surnames from the American population or the relevant country and in the same way DNA and the Y chromosome is passed from generation to generation, so are surnames, so by generating a link between the specific inherited marker and the surname, the door opens up.
Using this technique the Y chromosome can be taken from evidence left at a murder scene or from DNA deposited on the seal of an envelope, entered into the system and a potential surname is presented to the observer.
This technique can therefore provide the police immediately the name of potential suspects, vastly narrowing the field of investigation, coupled with the location of the likely perpetrator, the job of apprehending a killer is one step closer.
But this forensic advancement used in the Zodiac case could shake the murderers family tree to its roots and literally drop the killers name directly into the palms of our hands.