Matthew Perry death: How can doctors charged continue to practice after arrest?

The Medical Board of California said it's still investigating the doctors charged in the death of Matthew Perry and said it will take "appropriate action."

Five people were charged in connection with the actor's death from a ketamine overdose last year, including the actor's assistant and two doctors - Dr. Mark Chavez and Dr. Salvador Plasencia.

"The Board is committed to protecting the public and is actively investigating these matters and will take appropriate action specific to the facts, circumstances, and available evidence," said the board in a statement Thursday.

Plasencia reopened his medical clinic in Calabasas Tuesday.

Attorneys for Plasencia said while the clinic was reopened, he did not go in to treat patients. There was a sign on the door that said he is a defendant in a pending case and charged with felony offenses.

The sign also said he cannot prescribe any controlled substances, but still keeps his medical license.

Plasencia is accused of selling the ketamine to Perry, which ultimately caused his death. At the time, the actor had been undergoing ketamine infusion therapy to treat his depression.

How common is it for a doctor to continue practicing after an arrest?

Though Plasencia's attorneys said he hasn't treated any patients, legally , he can.

For now, a court order requires the following:

• A disclaimer on the clinic's door regarding the case

• Patients must sign a form acknowledging they know they case is pending

Both the notice and the form must state that Plasencia has surrendered his DEA registration and is not able to prescribe any controlled substances.

In a statement, the board said, "regarding the California medical licenses of both physicians, the board has not imposed any discipline on the medical licenses of Dr. Mark Chavez and Dr. Salvador Plasencia at this time."

So on one hand, you have the criminal proceedings and on the other, you have the medical board's investigation.

One case that could shed light on how these parallel proceedings play out is the case of Dr. Conrad Murray, who was convicted of involuntary manslaughter in the death of Michael Jackson.

In that case, Murray's medical license was suspended when he was convicted, which was almost two years after he was charged.

The Medical Board of California's public affairs director told USC Center for Health Journalism that the board had urged the court to place restrictions on Murray.

The court did impose restrictions in early 2010, including prohibiting Murray from administering anesthetics.

About a year later, the court ordered he stop practicing medicine in the state of California. He was convicted 10 months later.

The board said it would have acted if the court did not agree to its recommendations and stressed the public was being protected as Murray pursued his right to due process and as investigators pursued evidence in the case against him.

At this point, the medical board has not taken any disciplinary action against the two doctors but it's possible that, like in Murray's case, restrictions could triggered by the court.

Who is Dr. Salvador Plasencia

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

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 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 in court, where he wore street clothes and was in handcuffs and leg chains. He was released on a $100,000 bond.

READ ALSO: 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.

"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.

"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 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.

What's next?

On Friday, Aug. 30, Chavez is set to plead guilty in court where a sentencing date will likely be set. On Oct. 8, Plasencia is due back in court for his trial, but the U.S. Attorney is expecting this date to change.

A week later on Oct. 15, Sangha is due back in court for her trial. Attorneys believe a plea deal is very likely before the trial resumes.

Sentencing dates have not yet been set for Perry's assistant or alleged distributor.

Their sentencing dates are under seal, but the U.S. Attorney is hoping to get them unsealed as soon as possible.

ABC News and The Associated Press contributed to this report