(CBS NEWS) The same company that investigated Washington Navy Yard gunman Aaron Alexisfor his security clearance also did a 2011 follow-up investigation of Edward Snowden, the former National Security Agency systems analyst who leaked documents about the NSA.

The company, USIS, said in a statement Thursday it conducted Alexis’ background check in 2007 for the Office of Personnel Management, but that it couldn’t elaborate.

USIS was working as a contractor for the Office of Personnel Management (OPM) at the time.

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