The court properly denied defendant's suppression motion. Late at night, in a desolate, drug-prone alleyway, an experienced narcotics officer saw defendant take an unidentified object from his boot or sock and give it to another person in return for what appeared to be money. This provided probable cause for defendant's arrest ( see People v Jones, 90 NY2d 835). Even without any police training, "any person observing defendant . . ., using good common sense, would have, in the totality of circumstances, concluded that defendant was involved in the sale of narcotics" ( People v Graham, 211 AD2d 55, 60, lv denied 86 NY2d 795). While defendant argues that the transaction could have involved the sale of a lawful item, he has not identified what type of lawful item might be stored in a sock and sold in the manner described above. Defendant's conduct was "hardly the type of behavior engaged in by legitimate street vendors, who advertise their wares openly" ( id.).