When did they do that ?
Quoting:
Cupp, 394 U.S. 731 (1969), was a United States Supreme Court case that affirmed the legality of deceptive interrogation tactics.
Also:
Most importantly, the law actually permits investigators to utilize psychological manipulation, including lying, in order to obtain evidence of a crime.
Because jon said that the Polish police are trained to defuse
Police lying during interrogations has nothing to do with defusing.