Indian Law Enforcement Improvement Act - Provides for improvement of law enforcement and determination of civil and criminal jurisdiction and law in Indian country. Title I: Determination of Civil and Criminal Jurisdiction and Law - Provides that by presenting a resolution adopted by tribal referendum the tribe shall be able to have the Federal Government reacquire civil or criminal jurisdiction from a State in any case in which specified conditions are met. Sets forth procedures to be followed by the Secretary of the Interior in effecting such changes. Title II: Improvement of Law Enforcement on Indian Reservations - Directs the Secretary of the Interior to implement programs to improve law enforcement and the administration of justice within Indian reservations and Indian country. Authorizes the Secretary to make grants for programs and projects as suggested by this Act with law enforcement improvement as their goal.