IANAL, but given there is no statute of limitations on prosecuting most major felonies like murder. it seems that the legislators would just change the law after a felony was committed allowing for the prosecution of the crime. At least from my limited knowledge they have done that in the past to fix issues, so I am not sure how this would be any different.
I do think it is interesting how the legislating bodies allow this type of stuff to occur (and not fix it timely), but it seems more a procedural technicality then a way to get away with anything. In addition, I am sure a prosecutor would allege the crime originated outside the jurisdiction giving the place where the "thought" or "plan" occurred jurisdiction to prosecute. And in the end it would be heard by a jury in that jurisdiction and regardless of the truth they would get their conviction.
This is a great story to tell (as the book written from it likely does) but no one would likely get away with a major crime if they were caught just because it occurred in this area. Petty crimes, I bet would go unnoticed and never be brought to a hearing because of the quagmire, but not a major felony.
