Matthew Perry's Disgraced Ex-Assistant Sentenced to Nearly 4 Years in Prison — After He Gave 'Friends' Actor the Ketamine That Killed Him

Matthew Perry's former assistant has been sentenced to nearly four years in prison, RadarOnline.com can report, for giving the beloved actor the dangerous ketamine that would kill him.

Kenneth Iwamasa, Perry's assistant and friend of 25 years, pleaded guilty to one count of conspiracy to distribute ketamine, causing death, and admitted to repeatedly injecting the actor with drugs, including on the day he died, October 28, 2023.

Iwamasa had been accused of "repeatedly" injecting the 54-year-old star with ketamine "without medical training."

The troubled actor was found dead in his hot tub by Iwamasa when he returned from running errands, after he shot the actor "up with a big one," according to his plea agreement.

Perry's cause of death was determined to be "acute effects of ketamine," and his assistant pleaded guilty to one count of conspiracy to distribute ketamine, causing death.

The sentencing comes after several days of explosive and emotional testimony from Perry's family, including from his mother, Suzanne, who pulled no punches in making it clear she holds Iwamasa responsible for the death of her son.

"Matthew trusted Kenny. We trusted Kenny. Kenny's most important job – by far – was to be my son's companion and guardian in his fight against addiction," Suzanne wrote in her victim impact letter. "His number one responsibility – ensure that Matthew remained what he wanted to be: drug-free.

"Kenny knew, should he feel unduly pressured, that with one phone call to any number of the people in Matthew's orbit, reinforcements would be on the way, and his job would be safe. But instead of protecting Matthew, he aided and abetted illegal drug taking, arranged for one source of supply, then another."

She continued: "[He] shot the drugs into Matthew's body, though he was not in the least qualified. He did it even though he could see, anyone could have seen, it was so obviously dangerous. And he did it again and again."

Iwamasa was one of five suspects arrested in connection with Perry's ketamine overdose death.

Doctors Salvador Plasencia and Mark Chavez, Perry's director friend Erik Fleming and Jasveen 'Ketamine Queen' Sangha were also arrested on charges connected to the 17 Again actor's passing.

U.S. Attorney Martin Estrada confirmed the five suspects were arrested as part of a "broad underground criminal network" involved in "taking advantage" of the actor and causing his fatal ketamine overdose.

It was also revealed Perry and his assistant spent at least $55,000 on illicit ketamine injections in the 29 days leading up to the agonized actor's overdose death.

Iwamasa and Dr. Plasencia "exchanged thousands in cash for bottles" of the deadly anesthetic, and Dr. Plasencia and Dr. Chavez were caught discussing the illicit drug deals via text message.

Jasveen Sangha, the woman known as the "Ketamine Queen" who provided drugs that killed Perry, was sentenced to 15 years in federal prison and three years of supervised release in April 2026.

Sangha pleaded guilty in September 2025 to one count of maintaining a drug-involved premises, three counts of distribution of ketamine, and one count of distribution of ketamine resulting in death or serious bodily injury.

Authorities alleged that she sold approximately 50 vials of ketamine to Matthew for $11,000 — including the batch that led to his passing.

"These defendants took advantage of Mr. Perry's addiction issues to enrich themselves. They knew what they were doing was wrong. They knew what they were doing was risking great danger to Mr. Perry, but they did it anyway," Estrada said.

"In the end, these defendants were more interested in profiting off Mr. Perry than caring for his well-being."