A San Jose drug dealer known as “Madman” has agreed to plead guilty to selling fentanyl-laced pills to Los Gatos High School students. Prosecutors said as part of his guilty plea, Simon Armendariz will be sentenced in December to a 12-year prison term.

In a press release, prosecutors said Aremendariz late last week pleaded guilty to all charges and allegations, which included four felonies for selling drugs to minors, misdemeanors for possession of ammunition by a prohibited person, possession of fentanyl and two-strike prior offenses.

The Santa Clara County District Attorney’s Office said several students carried Narcan with them in case they overdosed on the toxic drug. One of the victims – a 15-year-old girl – overdosed in a bathroom at a Narcotics Anonymous meeting, prosecutors said.

As well as other misdemeanor offenses. Armendariz, 23, - who sometimes called himself “Risky or Madman” - will be formally sentenced in December in San Jose.

“Just so everybody knows: fentanyl kills,” District Attorney Jeff Rosen said in a statement. “Just so everybody knows: if you sell fentanyl to teenagers, then our prosecutors will do everything in our power to send you to prison for a very long time.”

The investigation began when the Santa Clara Police Department responded to an overdose report. The pill on which the teen overdosed – a counterfeit Percocet pill laced with fentanyl – was traced back to Armendariz.

The police, a county drug task force, and DA investigators traced the drugs to several other students, one of whom would get the $10 pills delivered from the dealer at school before first period or at the nearby parking lot of St. Luke’s Episcopal Church in Los Gatos.