A San Diego doctor has become the third person to plead guilty in connection with the drug overdose death of actor Matthew Perry, a case that has cast the spotlight on the dangers of ketamine abuse in prescription practices.

Dr. Mark Chavez entered his plea in a California courtroom on Oct. 2, pleading to a felony count of conspiracy to distribute the surgical anesthetic ketamine, and admitting to his role in supplying the drug that led to the tragic death of the “Friends” star.

Perry was found dead at his Los Angeles home by his live-in assistant Kenneth Iwamasa on Oct. 28, 2023, with a medical examiner later ruling that ketamine was the primary cause of death of the 54-year-old actor.

Five people, including Chavez, have been charged in connection with Perry’s death. The others are Iwamasa, Dr. Salvador Plasencia, an acquaintance of the actor named Eric Fleming, and Jasveen Sangha, referred to in court documents as the “The Ketamine Queen.”

Two other defendants besides Chavez have pleaded guilty. Iwamasa has pleaded guilty to one count of conspiracy to distribute ketamine causing death, while also admitting to repeatedly injecting Perry with ketamine without medical training, including performing multiple injections on Perry on the day that he died. Fleming has pleaded guilty to one count of conspiracy to distribute ketamine and one count of distributing ketamine resulting in death.

Chavez agreed to cooperate with prosecutors as they pursue more-serious charges against Plasencia, who is alleged to have given ketamine to Perry directly.

Plasencia faces seven counts of distributing ketamine and two counts of altering and falsifying documents related to the federal investigation into the circumstances of Perry’s death. Sangha has been charged with one count of conspiracy to distribute ketamine, one count of maintaining drug-involved premises, one count of possession with intent to distribute methamphetamine, one count of possession with intent to distribute ketamine, and five counts of distribution of ketamine.

Both Plasencia and Sangha have pleaded not guilty.

In court on Oct. 2, Chavez admitted to supplying 22 vials of ketamine and nine ketamine lozenges to Plasencia, using fraudulent prescriptions.

Matthew Binninger, Chavez’s attorney, told reporters outside the courthouse that, with his plea, his client is accepting responsibility for his actions.

“Mark entered his plea of guilty, and that’s now public record,” Binninger said. “You accept responsibility and then you set sentencing.”

While Chavez faces a potential sentence of up to 10 years in prison, his plea and agreement to cooperate with prosecutors mean that he’s likely to be sentenced to less time.

All five defendants were charged in an 18-count indictment unsealed on Aug. 15 , with prosecutors saying that the penalties for those convicted could be severe.

“By filing these extensive and serious charges, we are sending a clear message,” U.S. Attorney for the Central District of California Martin Estrada said during a news conference. “If you are in the business of selling dangerous drugs, we will hold you accountable for the deaths that you cause.”

The Associated Press contributed to this report.