U.S. Border Patrol agents were involved in a deadly shooting while assisting the Tohono Oodham Police Department.

The shooting took place on Thursday, May 18 around 10 p.m. on the Tohono Oodham reservation near Ajo, Ariz.

The incident is under review by Customs and Border Protections Office of Professional Responsibility, with FBI & Tohono Oodham Police investigating as well.