A narcotics investigation led to the arrest of four Salinas residents yesterday. Authorities say that Salinas police aided by other law enforcement agencies served search warrants at four different residences. 48-year-old Jorge Gasca and 62-year-old Paul Bruno were arrested on drugs, sales, and weapons charges. 41-year-old Sarina Frias and 24-year-old Vincenta Flores were arrested for drug possession. 1.5 pounds of methamphetamine, 24 grams of cocaine and heroin, and five pistols were seized in the raids.