SAN JOSE -- A veteran San Jose firefighter was arraigned Tuesday on charges of drug dealing after he allegedly sold meth to an undercover officer but no charges have been filed on allegations that he gave drugs to and had sex with an underage teen.

Mario Enrique Cuestas, 53, of San Lorenzo, did not enter a plea during the brief hearing where he answered to three felony counts involving the sale and possession of methamphetamine. Judge Deborah A. Ryan set his bail at $75,000, and he was taken back to protective custody at the Santa Clara County Jail.

Cuestas was arrested Thursday at the headquarters for the San Jose Fire Department, where he was recently named its director of public outreach, making him the agency's primary liaison with schools and community and church groups. He has worked with SJFD for 20 years, most of them as a fire engineer and driver and partly as a fire investigator.

"This is an individual who occupies a position of trust and authority, and he violated that," said Deputy District Attorney Patrick Vanier, supervising attorney for the narcotics division at the District Attorney's Office. "It underscores the seriousness of this case."

Vanier said an investigation into an alleged sexual relationship between Cuestas and a 17-year-old boy is ongoing and is being reviewed by another set of prosecutors.

Cuestas appeared stoic and morose during the court hearing, where several supporters sat in the gallery. He made a brief appreciative gesture to the group before he was led away. The supporters walked out of the courthouse without acknowledging questions from reporters.

Charging documents filed Tuesday revealed more details about the sting that led to Cuestas' arrest, which capped a swift two-month investigation sparked by a tip to agents with the Santa Clara County Specialized Enforcement Team, a squad of local police officers funded and overseen by the California Department of Justice.

The tip led to agents contacting Cuestas and arranging a lunchtime meth buy. An undercover officer met with Cuestas on Jan. 17 at an undisclosed restaurant in San Jose where the suspect allegedly sold an eighth of an ounce of meth for $150. That was followed by Cuestas allegedly making another offer a week later.

Vanier said it was clear during the officer's interaction with Cuestas that he was a firefighter. He was observed wearing a San Jose Fire Department lanyard attached to his work badge, and the undercover agent asked about it.

"The officer made note of it, but Mr. Cuestas did not acknowledge it, and changed the subject," Vanier said.

At the time of his arrest, authorities searched his car and found a small amount of meth, which investigators believe Cuestas used recreationally. Where he got the drugs was not immediately clear, and there is no record of previous drug arrests or convictions associated with Cuestas in Santa Clara County.

State Department of Justice spokeswoman Michelle Gregory said last week that the investigation also yielded information that he allegedly had a sexual relationship with a 17-year-old boy to whom he gave drugs. Gregory said the boy has been cooperative with authorities.

The drug counts carry a maximum sentence of four years and eight months in state prison.

Cuestas' arrest shocked the fire department and greater San Jose community, where he was a well-regarded and vocal figure who often took leadership roles within the rank-and-file. He has since been placed on unpaid administrative leave.

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