The American Civil Liberties Union filed a lawsuit in San Diego federal court Thursday against Customs and Border Protection and the Department of Homeland Security, arguing that the agencies did not produce a document that the ACLU requested under the Freedom of Information Act, reports the San Diego Union-Tribune.

The document is a report, commissioned by Customs and Border Protection, that was issued in 2013 by the Police Executive Research Forum, an independent third party.

The report's details were first published by the Los Angeles Times. The investigators analyzed 67 Border Patrol case files of civilian shootings, including 19 fatalities. The report concluded that Border Patrol agents have used excessive force and that the agency didn't properly investigate these deaths.