To what extent may the people elicit police testimony regarding the hierarchy and intricacies of street-level narcotics operations when a single sale is charged?

The issue was addressed in People v. Brown, 97 NY2d 500 (2002), where in a 'buy and bust' no drugs or prerecorded buy money was found on defendant's person. The Court upheld expert testimony concerning multi-level narcotics transactions to explain why those accused of selling narcotics may not be in possession of either the money or drugs shortly after the sale.

Brown, however, cautioned that 'such expert testimony is not necessarily proper in every drug sale case where a defendant asserts a misidentification case.' Significant, is that defendant Brown argued that he had been misidentified as the seller at the time of his arrest. 'The mere absence of drugs or marked …