Question: Whose authority were the Mexican police under that had a shootout with the CJNG in 2015?
Sentence (from "2015 Tanhuato–Ecuandureo shootout"): On May 22, 2015, a three-hour shootout broke out between the Mexican Federal Police and alleged members of the Jalisco New Generation Cartel (CJNG) in Tanhuato and Ecuandureo, Michoacán, leaving 43 dead.
Relevant evidence: Yes