I've read about this on several sites, so no link, other than here.
From the Social Science Research Network you will find, as the site says:
The dataset records state laws in all fifty states and the District of Columbia over the last several decades. For each reform we record the effective date, a short description of the reform, whether or not the jury is allowed to know about the reform, whether the reform was upheld or struck down by the states' supreme courts, as well as whether it was amended by the state legislator.
The author is Ronen Avraham from Northwestern U. Email Avraham a thank you if the paper helps.
