The separation of the US judiciary individual  state court systems creates a systemic obstacle to curing past damage created by flawed CSI expert testimony. Montana is the example used in this article to put this in a sharper focus.

http://mtstandard.com/crime-and-courts/some-states-review-flawed-hair-analysis-convictions-but-so-far/article_078e5c5d-2d97-503f-b9fa-af337aa08585.html