Born February 24th 1928, Jack Tarrance is a late addition to the Zodiac suspect list, after his name was put forward by his stepson Dennis Kaufman in 2007. He attempted to back up his claims by producing a blooded knife, disturbing images on rolls of film, handwriting samples of his stepfather he claimed were very similar to the Zodiac letters and more interestingly a black hood found rolled up and concealed within the confines of an amplifier. It was claimed, the very executioner's costume worn by the Zodiac Killer during the murder of Cecelia Ann Shepard and the attempted murder of Bryan Calvin Hartnell at Lake Berryessa on September 27th 1969.
Jack Tarrance died in 2006, but had previously spent time as a serviceman in the Navy and Air Force, tying in with the military boots worn by the killer during the Lake Berryessa attack. Trained as a radio operator, it provided him with the opportunity to learn coding that may have inspired the cryptograms and codes contained in at least four of Zodiac's communications, possibly more. The composite sketch created from eyewitness recollections in the aftermath of the murder of Paul Stine on October 11th 1969 bore a hauntingly near likeness to Jack Tarrance.
However, Dennis Kaufman has come under widespread criticism for some of his claims and has been roundly discredited by many people. The FBI later performed DNA and handwriting analysis on the items of interest submitted in 2010, but these tests were deemed inconclusive, ruling Jack Tarrance neither in, nor out of the Zodiac mystery. Dennis Kaufman appeared on a Discovery Channel documentary presented by true crime writer Aphrodite Jones in 2010, where he outlined his belief that his stepfather was in all likelihood the Zodiac Killer. The part featuring Kaufman begins at 14.56 into the video.
He recruited Nanette Barto, a court certified forensic document examiner to take a look at Jack Tarrance's handwriting and compare it to the letters written by the Zodiac Killer. (37.11 in video). She thoroughly examined the handwriting exemplars provided and when prompted by Aphrodite Jones, she stated "I think Dennis Kaufman really does have the stepfather of the Zodiac Killer". However, Nanette Barto's impartiality has subsequently been called into question regarding certain aspects of the above suspect.