Commonwealth v. Perez, 90 Mass. App. Ct. 548

Police received a tip from a confidential informant that Luis Reyes (alias of defendant Santos Perez) was selling heroin from 172 Hathaway St., Apt. 3 East, and provided aliases, birthdates, and a description of a rental car used for deliveries.
Officer Gonzalez corroborated aliases and photos in police/RMV databases and observed a car described by the informant leaving and returning to the building on multiple occasions.
Within 72 hours of the warrant application, officers supervised a controlled buy in which the informant purchased heroin from the defendant; the informant later delivered heroin to Gonzalez.
Surveillance on a separately reported delivery led to a hand-to-hand sale at a gas station; the purchaser (Combs) was stopped and found with ~11.9 grams of heroin, and later the defendant was stopped with large amounts of cash and multiple phones.
Officers secured the apartment and obtained a search warrant; execution of the warrant yielded a substantial quantity of heroin and the defendant was indicted for heroin trafficking and possession with intent to distribute.

Issue	Commonwealth's Argument	Defendant's Argument	Held
Whether the warrant affidavit established probable cause under Aguilar‑Spinelli and art. 14 to search the apartment for heroin	Corroboration by police surveillance, results of a supervised controlled buy, accurate predictive information (times, vehicle), and database/photo matches cured any informant reliability gaps and established a nexus to the apartment	Informant lacked demonstrated veracity in the affidavit and police observations alone did not sufficiently tie drug activity to the apartment; therefore affidavit failed Aguilar‑Spinelli and lacked nexus	The affidavit read as a whole supplied sufficient probable cause: corroboration and a supervised controlled buy established informant reliability and, coupled with police observations, a sufficient nexus to justify the warrant

Aguilar v. Texas, 378 U.S. 108 (U.S. 1964) (sets out basis-of-knowledge and veracity prongs for informant-based probable cause)
Spinelli v. United States, 393 U.S. 410 (U.S. 1969) (applies Aguilar prongs to informant tips)
Brinegar v. United States, 338 U.S. 160 (U.S. 1949) (probable cause deals with practical probabilities)
United States v. Ventresca, 380 U.S. 102 (U.S. 1965) (preference for warrants; review of affidavits on their four corners)
Commonwealth v. Upton, 394 Mass. 363 (Mass. 1985) (Aguilar‑Spinelli framework under art. 14 and need to consider corroboration)
Commonwealth v. Escalera, 462 Mass. 636 (Mass. 2012) (nexus inquiry and reading affidavit as whole)
Commonwealth v. Tapia, 463 Mass. 721 (Mass. 2012) (informant reliability and Aguilar‑Spinelli application)
Commonwealth v. Pina, 453 Mass. 438 (Mass. 2009) (limitations on inferences from limited police observations)