Well this is a welcome site:
Breaking News! Nation-wide Study of Law Enforcement under Public Law 280 Published
Final Report: Law Enforcement and Criminal Justice Under Public Law 280
Professors Carole Goldberg and Duane Champagne are co-principal investigators for a research grant from the U.S. Department of Justice to conduct the first nationwide study of law enforcement under Public Law 280. This two-year, $300,000 grant collected crime and victimization data, and carried out more than 300 intensive interviews with law enforcement officers, tribal officials, criminal justice personnel, and tribal members at 16 different reservation sites in Public Law 280 and non-Public Law 280 states. This report analyzes positive and negative aspects of state criminal jurisdiction in Indian country, and recommends strategies for improving law enforcement for reservations currently subject to Public Law 280.
Much more info there on CA Tribal Sovereignty as well: