Ohio amended Criminal Rule 16 in 2010 to include "open discovery" rules. The rules required the prosecution to share all exculpatory information to the defense. If the defense sends a discovery request, the defense has a "reciprocal duty of disclosure" to share their files with the state, even if the state never asked for them. Also, the prosecution is allowed to mark certain documents as for defense counsel eyes only.
The Ohio Disclosure Rules are available here.
In 2004, Governor Mike Easley of North Carolina, signed into law a bill that requires prosecutors to share files in all felony cases. The discovery statute requires district attorneys to share their investigative files in felony cases to defense lawyers who request them prior to trial. The law requires that investigator notes, defendant and witness statements, test results and a list of probable witnesses for the trial be included in the files from the prosecution. The defense is also required to turn over such things as the state with witness lists and details about the grounds on which they plan to defend their client.
The North Carolina Disclosure Statute is available here.