There is no doubt that Arthur Lee Allen was a nasty piece of work. He was a child molester, with multiple complaints against him and one conviction for sexual penetration of a minor.
But ironically, he spent most of this life being persecuted for crimes for which he was almost certainly innocent.
It was often said that Allen fit the description of the Zodiac killer, but it wasn't true. Composites of eyewitness descriptions of the Zodiac suggested a man who was short, stocky, with a gaunt face, close cropped hair, wore glasses, and was in his early 30s in 1969. But in 1969, Allen was 6 feet tall, conspicuously obese, moon-faced, almost completely bald apart from a "monk's tonsure" above his ears, did not wear glasses, and whilst he was in his late 30s, with his poor health he looked much older. (Some later pictures show Allen much more gaunt; these were taken more than a decade later, when he was dying from kidney disease and had lost a lot of weight.) It is therefore not too surprising that Kathleen Johns -- the only adult witness to get a good, clear look at the Zodiac Killer over an extended period of time -- stated emphatically and unequivocally that Allen was not the man who kidnapped her.
A social misfit, Allen could rarely provide witnesses for his time away from work. However contrary to some claims, he did have a fairly good alibi for one of the attacks, the one at Lake Berryessa. Unfortunately for him, for some inexplicable reason the Vallejo police did not bother to investigate his alibi until long afterwards, when it was too late to identify his witnesses, so the alibi was considered inconclusive. But that wasn't Allen's fault; having been questioned about a murder, he presumably expected his story to be checked out immediately.
Many claims about Allen can be seen to be misreporting. His typewriter is said to have matched a Zodiac confession note; in fact, it was merely the same model (a very common model for the era), and the individual keys were not matched by police forensics tests.
There are numerous other reasons to believe Allen innocent of (these) crimes. He co-operated fully with the police from the beginning until he grew sick of the harassment after more than a decade, and submitted to several tests, without warrant, giving him no time to prepare. And yet all of these tests cleared him:
- Fingerprints: definite non-match to those found at Zodiac crime scenes (Blue Rock Springs and Presidio Heights.)
- Handwriting samples, provided immediately on request, from both hands. The police "shopped" over at least seven handwriting analysts, looking for one who would condemn the suspect, but they all agreed that he not only wasn't a match, the writing was so dissimilar it couldn't be faked.
- Polygraph test: undertaken voluntarily, passed as innocent and concealing nothing (it included a confession that he was "very bad with children.") Asked to submit to a more sophisticated polygraph in the 1990s, Allen had just printed out his consent for this test when he died from his kidney disease.
- DNA tests: DNA taken from the stamps used on the Zodiac's letters was a definite non-match for Allen.
In addition, police executed numerous search warrants against his property, over a period of many years, and also persuaded his brother to conduct an illegal search for them. Up until the 1991 search, none of these searches turned up anything suspicious, nor indeed anything to connect him to the case at all. The 1991 search found eight firearms and some explosives. As a convicted felon (paedophilia) it was illegal for him to have these, however it was determined that none of them was in any way related to the Zodiac case. This was more significant than it sounds: this search was motivated, in part, by a profiler
's report that if Allen was a serial killer
, he may still possess "souvenirs" of his crimes, and after so many years might become careless about hiding them. But they found nothing.
So why did the police maintain an interest in Allen for so long, when every available scrap of evidence strongly indicated they were barking up the wrong tree? It was largely due to a report by one-time neighbour Don Cheney, who represented himself as a friend of Allen's. Cheney reported to the police that prior to the Blue Rock Springs killings, Allen had discussed with him an idea for a novel which was an almost exact blueprint for the killings. However, Cheney's story changed slightly every time he told it, it contained numerous absurd and provably false elements (such as that Darlene Ferrin's father was a mob boss and the impoverished Allen was actually one of his hit-men), he couldn't account for why he had waited 2 years to come forward with his story, and he was a very long way from being Allen's friend. In fact, Cheney had earlier complained that Allen had molested his daughter, and had been very dissatisfied with the response. He still loathed Allen the pederast.
Loathed him enough to help a murderer to escape justice.