The FBI has taken over responsibility from the Department of Homeland Security's Division of Investigations, HSI.
In parallel, the border agency CBP has launched an internal investigation. In addition, the Department of Justice has launched a federal civil lawsuit in the case.
HSI's investigation, which so far has been conducted with assistance from the FBI, has been met with criticism, including after both the Minneapolis local prosecutor's office and Minnesota state investigators said they were denied access to evidence for their own investigations.
Nurse Alex Pretti was killed by federal border police during a protest in Minneapolis on Saturday.
