Commonwealth v. Castillo-Martinez, 104 Mass. App. Ct. 22

A Danvers police detective with extensive drug enforcement experience observed suspicious behavior in a Liberty Tree Mall parking lot, an area known for frequent drug transactions.
The detective saw Theodore Combs, previously identified by another officer as a THC dealer, waiting in his car for about ten minutes before the defendant, Kever Castillo-Martinez, arrived and entered Combs’ vehicle empty-handed.
The detective observed the two men sitting with their heads down, moving their arms, and leaning towards each other; Castillo-Martinez then exited with a plastic bag.
The detective, relying on his observations and information from the Gloucester detective, believed he had witnessed a drug transaction and had Castillo-Martinez stopped by police.
Upon being stopped, Castillo-Martinez admitted to wrongdoing and handed over a bag containing fifty vials of THC.
The trial judge suppressed the evidence, finding no reasonable suspicion for the stop; the Commonwealth appealed the suppression order.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether there was reasonable suspicion for the police stop	Detective's observations and reputation info about Combs supported reasonable suspicion of a drug transaction	No specific details of a crime observed; legitimate transactions could look similar; reputation info insufficient	Reversed suppression—detective had reasonable suspicion based on totality of circumstances

Commonwealth v. DePeiza, 449 Mass. 367 (articulable facts required for reasonable suspicion)
Commonwealth v. Stewart, 469 Mass. 257 (reasonable suspicion can exist without witnessing an actual exchange)
Commonwealth v. Kennedy, 426 Mass. 703 (reputation in the community as a drug dealer is a valid factor supporting probable cause)
Commonwealth v. Santaliz, 413 Mass. 238 (sets forth factors supporting probable cause in suspected drug transactions)
Commonwealth v. Daveiga, 489 Mass. 342 (standard of appellate review for motions to suppress)