Add Yahoo as a preferred source to see more of our stories on Google. A US military laser system shot down a drone near the US-Mexico border on Thursday, only for it to emerge that the aircraft belonged to Customs and Border Protection (CBP), prompting a swift closure of airspace and renewed political criticism.

Investigators tasked with running the internal Customs and Border Protection probe into the fatal shooting of Alex Pretti have had limited access to information and evidence obtained by the Department of Homeland Security's investigative agency (HSI) and the FBI, a law enforcement official briefed on the matter told CNN.