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. 

LENGTHY SACRAMENTO NEWS ARTICLE ON DENNIS KAUFMAN
https://www.newsreview.com/sacramento/zodiac-is-back/content?oid=283929
​
https://sites.google.com/site/zodiackillerjacktarrance/home

ABC News video featuring Dennis Kaufman
The Real Zodiac Killer - Thunderball Films
Dennis Kaufman and Charles Kaufman interview
​

1963 June 4th-The Domingos/Edwards Murders
1966 October 30th-The Cheri Jo Bates Murder
1966 November 29th -The Confession Letter 
1966 December- The Riverside Desktop Poem 
1967 April 30th- Bates Had to Die Letter
1968 December 20th-The Lake Herman Murders
1969 July 4th-The Blue Rock Springs Attack
1969 July 31st- Vallejo Times-Herald Letter and
408 Cipher Page1 (solved)
1969 July 31st- Examiner Letter and 
408 Cipher Page 2 (solved)
1969 July 31st - Chronicle Letter and
408 Cipher Page 3 (87% solved) 
1969 July 31st-The Complete 408 Cipher
1969 August 4th- Debut of Zodiac Letter
​1969 August 10th- Concerned Citizen Card
1969 September 27th- The Lake Berryessa Attack
1969 October 7th- The Good Citizen Letter
1969 October 11th-The Presidio Heights Murder
1969 October 13th-The Paul Stine Letters
1969 October 22nd-Call to Chat Show
1969 November 8th-The Dripping Pen Card and 
340 Cipher (partially solved)
1969 November 9th-The Bus Bomb Letter
1969 November 19th- The Riddler Notes
​1969 November 21st-The San Jose Code Letter
1969 November 28th-The Betsy Aardsma Murder
​1969 December 7th-The Fairfield Letter
1969 December 10th- Forecast for Cancer
1969 December 11th- Forecast for Leo
1969 December 16th-The Fairfield Letter 
1969 December 20th-The Melvin Belli Letter
1970 Feb 21st- The Hood and Garcia Murders
1970 March 22nd-The Modesto Attack
1970 April 15th-The Robert Salem Murder
1970 April 20th-"My Name is" Letter,
Cipher 3 (solved in 2019) and Bus Bomb Diagram
1970 April 28th-The Dragon Card
1970 June 26th-The Button Letter
Cipher 4 (solved in 2019) and Map
1970 July 4th-The Sleeping Bag Murders
1970 July 24th-The Kathleen Johns Letter
1970 July 26th-The Little List Letter
1970 Sept 6th-The Donna Lass Disappearance
1970 October 5th-13 Hole Postcard
1970 October 17th- "You Are Next" Postcard
1970 October 27th-The Halloween Card
1971 March 13th-The Los Angeles Letter
1971 March 22nd-The Pines Card
1971 Unknown- The 148 Character Cipher
​1971 July 13th-The Monticello Card
​1973 August 1st- The Albany Letter
1974 January 29th-The Exorcist Letter
1974 February 3rd-The SLA Letter
1974 May 8th-The Citizen Card 
1974 July 8th-The Red Phantom Letter
1974 December 27th- Christmas Card
​1975 November 3rd- The Belmont Letter
1978 April 24th-The 1978 Letter
1978 May 2nd- The Channel Nine Letter
1978 July 19th- The Scotch Tape Letter
1981 March 8th- The Peachtree Letter
1986 May 6th- The Freeway Letter
1987 October 28th- The 1987 Letter
1988 February 1st- The McDonald's Letter
1988 February 8th- The McDonald's Letter [2]
1990 September 25th- The Celebrity Cypher
1990 December-American Greetings Card
2001 January 10th- Happy New Year Card
​Unknown DMV Letter (possibly November 1971)