SAN JOSE — A year of undercover stings targeting downtown drug dealing has netted charges against nearly three-dozen suspects in what authorities hope will help clear the path for the area’s ongoing revitalization.

The charges, some of which have already led to convictions, were announced Wednesday by the Santa Clara County District Attorney’s Office, working off more than two-dozen clandestine narcotics deals conducted by the San Jose Police Department’s downtown services unit.

“We know sellers don’t want to sell to undercovers, and we want buyers to be aware that police are there,” unit supervisor Sgt. Mario Brasil said. “We’re trying to make it a thriving downtown again, and we’re saying to dealers, ‘You’re not welcome downtown.’ “

All told, 32 adult suspects whose ages ranged from 20 to 50, along with a 15-year-old, have been charged with drug sales-related offenses since police started serving search warrants in January, based on the undercover purchases spanning the entirety of 2015.

According to the district attorney’s office, some of the suspects have already pleaded guilty to their charges, with several cases still pending. Authorities did not release the identities or booking photos of the suspects Thursday.

The series of stings, dubbed “Buyout,” sought to identify known drug dealers in St. James Park, César Chávez Park, Fountain Alley and the intersection of First and Santa Clara streets. All have historically battled drug problems, particularly Fountain Alley, a walkway between First and Second streets notorious for illegal drug activity, and the site of a shooting as recently as last week.

Brasil said officers readily purchased crack cocaine, meth, and marijuana from suspected dealers and used the transactions to build enough evidence to apply for arrest warrants.

“My team did a fantastic job. Buying drugs is very dangerous, as drug dealers are usually armed. They take a lot of risk,” he said.

Most of the arrests occurred locally, but one of the suspects was tracked to Bakersfield, Brasil said.

Police have fielded increasing numbers of complaints about drug dealing downtown, particularly as the city has seen an increase in development and, correspondingly, residents in the area.

“The prevalence of drug dealers are precursors that can lead to more serious crimes. We cannot allow this type of activity to occur undeterred in our downtown,” SJPD Interim Chief Eddie Garcia said in a statement.

Contact Robert Salonga at 408-920-5002. Follow him at Twitter.com/robertsalonga.