The ACLU has released a report criticizing the passenger screening techniques used by the US Transportation Security Administration, after it obtained documents that showed the TSA itself determined its methods were unreliable and not based in science. The report comes almost three years after the ACLU submitted a FOIA request to the TSA asking for any records, training requirements, and any scientific background that proves that its passenger screening system worked.

The TSA has used a process called SPOT — Screening Passengers by Observation Techniques — to select people for additional questioning as they pass through airport security since 2007. The TSA had kept the details of exactly what it looked for secret, but a checklist was leaked to the press in 2015 that called out 92 specific actions, including exaggerated yawning, whistling before a screening interview, and the wearing of impractical clothes.

Along with the ACLU, many others have criticized the TSA for its methods, including Congress members from both parties, government auditors, and independent experts. In particular, the SPOT program came under fire for racial and religious profiling, with many travelers complaining that they were singled out because of their heritage. Some ex-TSA agents have also critiqued the program that they had to follow, with one calling it a “racial profiling program.”

This week’s report concludes that the TSA introduced the SPOT system without validating its effectiveness. From there, while the Authority argued that it did have scientific evidence for the success of the SPOT program in discussions with members of Congress and the Government Accountability Office, research and documents that it had on file actually reinforced the fact that “behavior detection is unscientific and unreliable.” Indeed, several studies included in the TSA’s files actually showed people trained to identify the 92 supposedly suspicious behaviors were actually worse at detecting lies than people who had not been trained at all.

The ACLU says documents were also discovered that raise questions about an anti-Muslim bias in the SPOT system. The report notes that one TSA presentation included a cartoon of a hijab-wearing mother and daughter arguing over “suicide bomber martyr Barbie,” and until 2012, training examples given to officers focused exclusively on Arab or Muslim terrorists. A memo sent in October 2012 reminded TSA trainers to “stress the importance of racial, ethnic, and religious neutrality,” noting some five years after the program was introduced that the lack of English proficiency was not necessarily an indicator of suspicious behavior.

The report concludes with two key recommendations: firstly, that all TSA behavior analysis programs are phased out; and secondly, that the TSA Administrator implement a “rigorous anti-discrimination training program for all TSA employees that emphasizes the impermissibility of racial and religious profiling, the dangers of implicit bias, and the importance of remedial measures to guard against unlawful profiling.” The TSA has yet to reply.