From the New York Times:
By 2011, the sheer number of C.B.P. misconduct cases had become so glaring — an average of one C.B.P. officer was arrested every day between 2005 and 2012, 144 of them for corruption-level offenses — that C.B.P. redefined the way in which misconduct was categorized, Tomsheck said. Certain misconduct cases would be deemed ‘‘mission-compromising’’ and others ‘‘non-mission-compromising’’; only the former would have to be reported to Congress….
In 2010, testifying before a Senate Homeland Security subcommittee, Tomsheck reported a staggering internal study: 60 percent of a pool of Border Patrol agents and customs inspectors who had been administered polygraph tests were deemed unsuitable for service.
The victims of Border Patrol misconduct are especially vulnerable. Illegal immigrants can’t get redress in U.S. courts in many situations and many wouldn’t even try–precisely because of their illegal status.