Sacramento Area Local News

SACRAMENTO (CBS13) ― Will handwriting reveal the identity of the zodiac killer?

Forensic document examiner Nanette Barto says she has spent more than 200 hours going through handwriting samples from Jack Tarrance, comparing them to high quality scans of the zodiac killer's letters.

"My opinion.. Jack is indeed the author of the zodiac letters," says Nanette Barto.

Jack Tarrance is the focus of an FBI investigation attempting to link the two men through DNA samples.

Tarrance's stepson, Dennis Kaufman, spent the past nine years building a circumstantial case against his late stepfather.

His evidence was enough to launch the FBI investigation.

While the FBI is focusing DNA, Dennis Kaufman has turned to Barto to try to establish a link between his stepfather and the zodiac through handwriting.

"I told him it was purely entertainment value I would even take a look at it," says Barto.

The forensic document examiner says she knew very little about the zodiac case when Kaufman approached her.

She agreed to look at the documents, but with her workload, let the samples sit on her desk for two months.

Once she started going through them, instead of discounting a connection, she reached a conclusion she never expected: Jack Tarrance authored the zodiac letter.

Barto had access to 55 samples of Jack Tarrance's handwriting, from diagrams and letters to reports he wrote while in the military. Barto says she compared the samples to high quality scans of the zodiac's writings.

Barto believes the zodiac attempted disguise his handwriting, but would fall back into his natural pattern.

"He got tired about here, and he got exhausted at this point," she says while referencing a letter attributed to the zodiac.

The page shows a clear difference in the writing style from the top of the page to the bottom.

Barto says when looking at handwriting it's not unusual to find 2 or 3 similarities between different writers and that if you can find 7 or 8 similarities may have a substantial match.

Barto says she found 42 similarities in the handwriting and believes there could be more.

Barto explains, "I found similar letter shapes, ticks, slants ..."

Many of the similarities are subtle. Things a writer wouldn't realize he was leaving behind.

Examples:

* Barto says she found several examples from both men where the dots of the "I" were not over the "I" but over the letter that followed.

* The examiner also found both men would print "g's" with straight tails. No loops on the bottom.

* Several letters had ticks marks, where the writer leaves a tiny ink mark to the left when finishing a letter.

* In printed "O's" Barto found tiny loops inside. She also found that both writers made their "O's" with flat backsides.

Barto also says she found examples where both jack and the zodiac would leave odd spacing in words themselves.

"Wis--dom. be--cause. They don't even look like they are connected," says Barto

Barto has studied for almost two years with the international school of forensic document examination and is court qualified. She has rendered opinion is more than 50 cases although not all of them have gone to trial.

Over the years the zodiac's writings have been examined by countless experts with a variety of interpretations.

Barto's current mentor and president of the school she attends, Bart Baggett, says he has seen Barto's findings.

"My conclusion, there are indications it is not the same author," says Baggett.

Baggett says this is the first time he can recall that the two have disagreed on a case but he says he has done extensive studies on the zodiac's letters and does not believe the zodiac attempted to disguise his writing.

"In this case there are similarities in letter formations for sure, but those similarities were not overwhelming in my eyes and the differences were so profound it doesn't make any sense it's the same author."

With the overwhelming interest in the zodiac and the multiple theories out there, Barto knows her finding are going to be scrutinized and criticized, but she says stands by her conclusion.

When asked how comfortable she is with saying that Jack Tarrance wrote the zodiac letters, Barto's responds is "I'm very comfortable."

There are plans to hand Barto's findings over to the FBI for review from the agency's own document examiners.

The FBI is still not commenting on the DNA results, saying only that this is still an active investigation.

(© MMX, CBS Broadcasting Inc. All Rights Reserved.)