Habeas
S. Ct. holding that state escape statute is not categorically a violent crime for purposes of the ACCA predicate conviction is a substantive change in the law to be made retroactively available on collateral review.
Circuit precedent that escape was a violent crime for purposes of one statute had a preclusive effect on whether it was a crime of violence with reference to another statute.
Very complex - here's our best guess: Access to S2241 Habeas depends on there being no effective remedy by a Habeas claim on motion. Where a deft has multiple potential predicates in the PSR and the indictment only lists three, but neither the sentencing court nor the PSR identifies the ones to be used in the ACCA enhancement, all potentially valid predicates are counted against the deft in considering jurisdiction for a S2241 writ unless petitioner can affirmatively establish that prior Habeas on motion would have been ineffective against the uncharged predicates. The argument that a challenge to a predicate was waived for procedural default, however, is a an affirmative defense on the merits - the relevant jurisdictional question for the S2241 writ is whether the writ on motion would have been an effective challenge.
[Again, don't rely on any of this for anything.]
Concurrence: No access to writ, as alternate bases for the enhancement establish that sentencing court did not rely on the challenged offense.
http://media.ca11.uscourts.gov/opinions/pub/files/201214989.pdf
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.