Officers responded to a call reporting suspicious subjects in the 8200 block of Arroyo Circle around 11:35 p.m., police said.
The officers encountered three men there who appeared intoxicated and found multiple prescription drug receipts for oxycodone, hydrocodone, alprazolam and diazepam in their possession. The receipts had other peoples' names, police said.
Police arrested the suspects, identified as Michael Gatch, 31; David Lam, 28; and Christopher Montarbo, 25.
As part of their investigation, officers obtained search warrants for a motel room in Morgan Hill and a home in the 1400 block of Amber Drive in Gilroy.
From the two residences, they seized more than 500 prescription drug pills, heroin that police believe the suspects intended to sell, and stolen physician prescription pads.
Montarbo and Gatch are Morgan Hill residents while Lam lives in Gilroy.
Police ask anyone with information on the case to call the department's anti-crime team at (408) 846-0350 or the Unified Narcotic Task Force at (831) 636-8622. To leave anonymous tips, call (800) 782-7463.