The FBI facial recognition system - not really tested?

So says the Government Accountability Office (GAO) -

"The FBI has entered into agreements to search and access external databases -- including millions of U.S. citizens' drivers' license and passport photos -- but until FBI officials can assure themselves that the data they receive from external partners are reasonably accurate and reliable, it is unclear whether such agreements are beneficial to the FBI and do not unnecessarily include photos of innocent people as investigative leads,"