SoCal doctors Salvador Plasencia, Mark Chavez at center of Matthew Perry's death case

The investigation into the death of Matthew Perry is putting the spotlight on the five people indicted by federal prosecutors, which include the actor's assistant, two Southern California doctors and a woman prosecutors call a "major street dealer".

The autopsy revealed the "Friends" actor died from acute effects of ketamine. At the time, he had been undergoing ketamine infusion therapy to treat his depression.

Five people have been charged in connection with the ketamine death of "Friends" star Matthew Perry, federal officials in Los Angeles announced.

Five people were arrested in connection to Perry's death -- Dr. Salvador Plasencia, Dr. Mark Chavez, Jasveen Sangha, Kenneth Iwamasa and Erik Fleming. They were described by the DEA as "greedy and reckless," taking advantage of Perry to profit for themselves. They're now facing federal charges in connection to his death.

Three of them have cut plea deals. The two that remain have pleaded not guilty in a case some experts say will be hard to beat.

Who is Dr. Salvador Plasencia

The U.S. Attorney's Office alleges Plasencia and the other defendants took advantage of Perry's addiction and knew that what they were doing was wrong. They point to a text message sent by him.

"(Plasencia) wrote in a text message in September 2023, 'I wonder how much this moron will pay,'" said U.S. Attorney Martin Estrada.

"That just shows evil, that is clearly not a medicinal text, that is a text of an opportunist who just wants to make money," said Civil Trial Attorney Tre Lovell.

Plasencia was arrested Thursday and charged with one count of conspiracy to distribute ketamine, seven counts of distribution of ketamine and two counts of altering and falsifying documents or records related to the federal investigation into Perry's death. He pleaded not guilty to the charges on Thursday in court, where he wore street clothes and was in handcuffs and leg chains. He was released on a $100,000 bond.

Related Story: What doctors want you know about ketamine, the treatment that killed Matthew Perry

His attorney Stefan Sacks said the doctor sold ketamine to Perry but insisted that he did not break the law.

"At the end of the day, Dr. Plasencia was providing medical treatment to Mr. Perry. He was operating in good faith under what he believed was his duty and whether or not there was a lapse in judgement in retrospect, it doesn't negate the fact that he was pursuing this with the best of medical intentions," Sacks said.

Patients of his in Calabasas were stunned to hear he was accused in Perry's death.

"He was professional. Nothing was prescribed," former patient Adam Gangi said. "He answered questions I had. His staff was friendly, so my experiences overall were positive."

"I'm disappointed but not surprised," patient Callie Beeman said, adding she no longer feels like she can trust Plasencia due to his involvement in Perry's case.

One patient of Dr. Salvador Plasencia said she was "disappointed but not surprised" he was accused in Perry's death.

"He looked at Perry as an object to get money out of him, not a person," Beeman said.

Plasencia, 42, graduated from medical school at the University of California, Los Angeles in 2010 and has not been subject to any disciplinary actions, records show. His license is due to expire in October.

Plasencia is facing a maximum of 120 years in prison, according to prosecutors.

Who is Dr. Mark Chavez

Also at the center of this case is Dr. Mark Chavez, a San Diego-based doctor, who worked to obtain the ketamine. He has agreed to plead guilty to one count of conspiracy to distribute ketamine.

Chavez sold ketamine that he had previously obtained by writing a fraudulent prescription to Plasencia, who then sold it to Perry's personal assistant, Kenneth Iwamasa, who has admitted to injecting the actor three times on the day he died.

Chavez, who used to run a ketamine clinic, also got additional ketamine from a wholesale distributor of controlled substances and falsified statements on forms, saying the drug would not be sold to a third party or distributed or used for any other purpose.

Chavez, 54, graduated from medical school at UCLA in 2004 and started a company, The Health MD, that appears to be a concierge medicine practice focused on longevity and fitness. Like Plasencia, Chavez has not been subject to any disciplinary actions, according to his records. His medical license expires in 2026.

Perry turns to 'ketamine queen' Jasveena Sangha

Federal authorities have charged five people in connection with the death of Matthew Perry, including Jasveen Sangha who has been dubbed the "ketamine queen."

Prosecutors said Perry later turned to Jasveen Sangha, known to her customers as the "ketamine queen," who provided the actor with cheaper ketamine -- 50 vials for $11,000.

She also pleaded not guilty to the charges. However, her bond was revoked by the judge and she remains in jail, with her next hearing two months away.

Iwamasa should be sentenced in the coming weeks for his role in Perry's death.

Looking at the timeline , federal prosecutors said this all happened within a 2-month span, adding that Perry fell back into addiction last fall before he died in October.

Here's how the investigation into the death of Matthew Perry unfolded, according to officials with the Department of Justice.

ABC News and The Associated Press contributed to this report