That is incorrect.
They told their supervisors about it. That isn't a coverup. But keep beating up on these two Hispanic Americans.
The trial testimony of the defendants, fellow Border Patrol agents who were on the scene and who arrived shortly thereafter, as well as taped radio communications showed that there were no supervisors at the scene at the time of the shooting. The agents knew they must report any discharge of a firearm and had just received training to this effect the day before this shooting. Further, Agent Ramos was a Border Patrol firearms instructor and a member of the evidence recovery team. He was well aware of this requirement as he had taught this to other agents. They did not report the discharge because they knew the shooting was not justified. Furthermore, based on their training and experience, they were aware of what law enforcement resources would be dispatched to the crime scene to investigate a shooting, including sector evidence team, the Federal Bureau of Investigation, and state and local law enforcement. [emphasis added]
It is a coverup if you: 1) ONLY "tell your supervisors" when other agents report the incident and your supervisor confronts you 2) collect the shell casings from the scene, in direct violation of protocols.
Your pandering references to "Hispanic-Americans" is amusing. The cops, who happened to be Latino, blew it.