There are some similarities between the Betsy Aardsma murder and the Riverside knife slaying of Cheri Jo Bates, in that both women were young college students with an independent mind and both were killed while visiting a library, albeit each crime was perpetrated at different times of the day, with one attack taking place inside the library and the other in an alleyway beside the library.
It has also been shown that a possible overlap in the timeline of Betsy Aardsma and Theodore Kaczynski occurred, when Betsy spent time at Ann Arbor from 1966-67, which apparently coincided with Ted Kaczynski for one year. In addition, it is claimed by some that he was also spotted in the Pennsylvania State library on November 27th 1969, just one day prior to her murder.
Despite the continuing links suggested to the Zodiac crimes, this murder falls short on a number of issues, namely, the Zodiac attacks tended to be committed in isolated retreats with limited possibility of capture, such as Lake Herman Road, Blue Rock Springs Park and Lake Berryessa. The only confirmed deviation to this was the taxicab murder of Paul Stine in Presidio Heights. Betsy Aardsma was killed in the daytime hours at approximately 4:45 pm in extremely high risk surroundings. Although the Zodiac Killer would often claim to be responsible for more killings than could be accounted for, no reference to this crime was evident in any of his subsequent correspondence.
Richard Haefner became a prime suspect in the Betsy Aardsma case - and details about this subject can be found by following the link below, which includes a composite sketch of a potential suspect from the library that afternoon.
(19th August 1956-28th November 1981)
Joan Lucinda Webster, a 25 year old Harvard graduate, disappeared after her arrival at Boston's Logan International Airport on 28th November 1981, and her remains were discovered nearly nine years later in April 1990 in Hamilton, Massachusetts.
The cause of her death remains undetermined, with nobody thus far having been charged with her supposed abduction and murder.
The case is constantly kept alive by determined individuals keen for a resolution to this 32 year old murder mystery.