Unless it was murder, or a plan of murder, or a plan to suicide, you don't do this.
AA is called Alcoholics ANONYMOUS for a reason. Now this lady will NEVER be able to trust AA, once out of jail.
The deed was already done, so the sponsor cannot claim to have been trying to prevent harm even! The sponsor's role is to get this person back on track with God, not with Columbia County.
They say in the Big Book that a sponsor is not a financial advisor, marriage counselor, or physician. I would add, policeman.
Tthe courts have proven that there is no expectation of privacy in AA unfortunately. You can be compelled to testify in a court of law and you could be charged with harboring information on a criminal act if you fail to report information to the proper authorities. Sharing in a ‘general way’ is advised on all levels IMO as a sponsor and as to what a sponsee shares. Lawyers and clergy are the only protected class when it comes to safeguarding secrets. The sponsor in this case could have advised that the person turn themselves in, after all how could they complete the 12 steps w/o properly cleaning house? Barring that she (I assume it was a woman sponsor) had every right to feel compelled to turn that person in by the nature of the crime - all my opinion of course.