Erik Prince, chairman and executive director of Frontier Services Group Ltd., walks to a closed-door House Intelligence Committee meeting on Capitol Hill in Washington, D.C., U.S., on Thursday, Nov. 30, 2017. Prince, best known for running the Blackwater private security firm whose employees were convicted of killing Iraqi citizens, was a presence during Donald Trump’s presidential transition and worked in part with Michael Flynn. Photographer: Aaron P. Bernstein/Bloomberg via Getty Images