Judgment, Su*141preme Court, New York County (Felice Shea, J.), rendered February 19, 1993, convicting defendant, after a jury trial, of criminal sale of a controlled substance in the third degree and criminal possession of a controlled substance in the seventh degree and sentencing him to concurrent terms of from AV2 to 9 years and 1 year, respectively, unanimously reversed, on the law, the convictions vacated and the matter remanded for a new trial.
In this prosecution for a single street-level sale of crack observed by two Housing Police officers through binoculars, it was reversible error to permit, over defense objection, background testimony from Officer Laccone regarding the "High Intensity Drug Trafficking Act” program of which they were a part and then to permit Officer Abad to explain the hierarchy of street-level drug organizations and how they operate in housing projects. Such testimony, particularly Officer Abad’s, was neither brief and limited to its expressed purpose of explaining the small amount of money ($4) and drugs (two vials of crack) recovered from defendant at the time of his arrest (cf., People v Garcia, 83 NY2d 817; People v Woney, 205 AD2d 480, Iv denied 84 NY2d 835), nor " 'carefully monitored’ ” (People v Stanard, 32 NY2d 143, 146). Although the Trial Justice attempted to set limitations on this testimony in her pretrial ruling, she later permitted the prosecutor to exceed such limitations. In short, in order to explain the paucity of money and drugs found on defendant, there was no need to go into a full fledged explanation of illegal drug organizations, thus clearly prejudicing defendant by escalating evidence regarding a single sale of illegal drugs into testimony suggesting that defendant was part of a large-scale drug trafficking operation (cf., People v Garcia, supra; People v Williams, 204 AD2d 183, Iv granted 84 NY2d 834). Concur— Murphy, P. J., Sullivan, Rubin, Kupferman and Ross, JJ.