(KRON) -- A Tracy man who allegedly sold drugs to children as young as 12 and had a 13-year-old helper has been arrested, according to the Livermore Police Department. The Livermore PD School Resource Sergeant received complaints back in April from parents and school staff about someone selling drugs to minors at local middle and high schools. Items allegedly sold included: Nicotine vapes Marijuana vapes Marijuana Psilocybin chocolate bars Alameda County DA recall effort ahead in early returns The suspect, police said, used social media platforms like Instagram and Snapchat to contact minors and sell the products. He often changed his online handles and used fake names to avoid detection, police added. The Livermore PD Crime Prevention Unit took over the case. Following four months of surveillance, multiple statements from witnesses and the execution of 10 search warrants, police said they identified Brian Gonzalez, 20, of Livermore as the suspect. A search of the suspect's apartment revealed more than $40,000 in cash and vape devices valued at around $125,000. Livermore PD said it also discovered Gonzalez was using a 13-year-old boy to help distribute the products. Livermore PD obtained an arrest warrant, and Tracy police arrested Gonzalez on Oct. 26. Gonzalez, police said, faces multiple charges that include: Selling and furnishing cannabis to a minor Possession of psilocybin for sale Possession of cannabis for sale Contributing to the delinquency of a minor Selling tobacco products without a license The case, police said, has been turned over to the Alameda County District Attorney's Office for prosecution.