Prosecutors in Ventura County once used a woman's distinctive signature — with its angular J and a D with a flowing tail — to help put her behind bars for the murder of her lover's wife.
The penmanship on a blood-stained, folded piece of paper led San Diego detectives to a serial-killing carpet cleaner who had slashed the throats of three women and a toddler.
And a handwriting expert was one of the first witnesses who testified in Los Angeles against the man accused of killing Bill Cosby's son, Ennis, to prove he wrote incriminating jailhouse letters.
Handwriting evidence has a long and sometimes controversial history. Now it appears likely to feature once again in a high-profile murder case as Los Angeles awaits the extradition of real estate scion Robert Durst from New Orleans in connection with the December 2000 killing of writer Susan Berman.
Among the evidence against Durst is a letter sent to Berman in 1999 that has handwriting strikingly similar to that on an anonymous note sent to Beverly Hills police at the time of Berman's killing, telling them that they would find "a cadaver" at Berman's house. In both samples, the writing is in all capital letters, and Beverly Hills is misspelled as "Beverley Hills."
In the final episode of a six-part HBO documentary about Durst and his links to three deaths, he admitted he wrote the letter to Berman but denied writing the "cadaver" note. Director Andrew Jarecki held up blown-up versions of the misspelled city from the envelope of each and asked, "Can you tell me which one you didn't write?"
"No," Durst responded.
Former Los Angeles County Dist. Atty. Steve Cooley said the handwriting provides prosecutors with compelling evidence to put before a jury.
"It is almost certain that he wrote both and fairly likely a lay person will come to that conclusion," he said.
Handwriting expert Sheila Lowe called the common misspelling of Beverly "very significant" — especially when combined with other similarities she said she spotted in the texts.
Lowe, president of the American Handwriting Analysis Foundation, said she'd seen the writing samples from the documentary posted online and thought there was "a strong probability" that both samples were written by the same person. In both cases, she said, there were Ls with a little curve at the bottom, calling it "a point of comparison." There are also Es in both samples in which the top cross bar is longer than the bottom cross bar and Ss in which the bottom part bulges larger than the top part.
In the HBO documentary, "The Jinx," forensic document examiner John Paul Osborn said there were unique handwriting characteristics between the "cadaver" note and materials filmmakers gave him as examples of Durst's writing. Osborn declined to talk to The Times, saying in an email that he is a potential witness and that a Los Angeles prosecutor assigned to the case had asked him not to speak to the media.
A trial could come down to "dueling experts" and how they view similarities and differences between the two sets of handwriting, said defense attorney and former federal prosecutor Adam Braun. Durst's attorneys, he said, will probably look for a credible expert to say that "Beverley" is a fairly common misspelling and that the similar handwriting characteristics aren't unique enough to prove the two notes are by the same person.
"It's certainly a field that seems to be more art than science," Braun said.
The scientific reliability of handwriting comparisons has been questioned over the years.
A 2009 report by the National Academy of Sciences said "there has been only limited research to quantify the reliability and replicability of the practices used by trained document examiners."
"The scientific basis for handwriting comparisons needs to be strengthened," the committee wrote.
At least one report suggests that hand-printed documents, such as the "cadaver" note in Berman's killing, are even more difficult to compare. The 2003 study published in the Journal of Forensic Sciences concluded that document examiners were almost twice as likely to make errors when viewing hand-printed writing as they were when viewing other types of documents, such as those written in cursive.
And two years ago, a federal judge in Wisconsin blocked a handwriting expert from testifying for the prosecution in a case involving threatening letters, saying the science behind it was "at best half-tested" and that there was even less scientific research on the identification of hand-printed documents.
Mark Denbeaux, a law professor at Seton Hall University in New Jersey who has researched handwriting evidence, said he often testifies against its reliability in court. Each person's handwriting style fluctuates whenever he or she writes, he said.
"It's so bogus," he said. "It's sort of like the emperor has no clothes."
If law enforcement in Los Angeles is "trying to look at letters and shapes and say these two letters are written by the same person," he said, "they have enormous problems."
But in California, jurors are often allowed to compare handwriting evidence and make up their own minds.
Such evidence was used to help convict Diana J. Haun, who Ventura County prosecutors said signed checks to buy a wig, a pantsuit and an ax before the 1996 kidnap-slaying of her lover's wife, and Mikail Markhasev in the 1997 fatal shooting of Cosby.
Last year, the state Supreme Court denied an appeal by David Allen Lucas, the carpet cleaner convicted of three murders and one attempted murder in San Diego County. Prosecutors argued that Lucas' writing matched that on a bloody note left at one of the crime scenes.
"For more than 100 years, we have recognized that expert handwriting comparisons have evidentiary value and that juries should 'form their own conclusion in reference to such similarity or resemblance,'" judges wrote in the opinion.
Times staff writer Richard Winton contributed to this report.