La. Public Health and Safety § 40:1391
The employees of the division shall cooperate and exchange information with any department or authority of the state or with other police forces, both within this state and outside it and with federal police forces, toward the end of achieving greater success in preventing and detecting crimes and apprehending criminals.
The department of public safety may, on request of any chief police officer of any local government unit in the state, assist such officer in the investigation of the circumstances of any crime and in the identification, apprehension, and conviction of the perpetrators thereof. For this purpose it may detail such employees of the division of state police for such length of time as it sees fit.
The department may, when so authorized by the governor, negotiate with appropriate officials of other states in the preparation of interstate compacts for police protection as authorized by the Act of June 6, 1934 (48 Stat. 909, c. 406; U.S. Code, Title 18, section 420), or other Acts of Congress. Such compacts as are negotiated shall be submitted to the governor and legislature for approval.
Now 4 U.S.C.A. § 112.
La. Public Health and Safety § 40:1391