Most of the handwriting experts are saying this is inconclusive. The one guy who claimed a "99%" match turns out to have been recently disqualified as a handwriting expert in court because of a lack of credentials.
More than one handwriting expert has claimed a high likelihood that the same person wrote both the yearbook sample and the ransom note. I also saw the one I suspect you are talking about explain why he was disqualified in a particular case. I don't recall him saying it was a lack of credentials. He said he has testified in more than 2000 other court cases.
If you look closely at the samples you will see what I am talking about. I can't imagine that the tails on the letters are anything but an exceedingly rare characteristic.