Who Is Kenneth Iwamasa? Matthew Perry's Assistant Sentenced For Ketamine Death

Kenneth Iwamasa, Matthew Perry's longtime assistant, was sentenced in Los Angeles on Wednesday to 41 months in federal prison for his role in the Friends star's ketamine death, closing the last major chapter in the prosecution tied to Perry's overdose.

The judge also imposed two years of supervised release and a $10,000 (£7,451.75) fine after Iwamasa admitted he injected Perry with ketamine, including on the day the actor died in October 2023.

The news came after a two-and-a-half-year federal investigation that uncovered a wider ketamine network around Perry, involving doctors, a middleman dealer and a supplier known in court reports as the 'Ketamine Queen.'

Iwamasa was the first of the five defendants to reach a plea deal, and the last to be sentenced.

Kenneth Iwamasa And Perry's Inner Circle

Iwamasa, 60, was far more than an employee on a call sheet. Court documents and multiple reports describe him as Perry's live‑in assistant and close companion of nearly 25 years, a man who moved into that strange territory between staff member and extended family.

By 2022 he was living in the actor's Los Angeles home, earning about $150,000 (£111,776.25) a year and, according to prosecutors, taking on responsibilities that explicitly included aspects of Perry's medical care.

Prosecutors said that, in the weeks before Perry's death, Iwamasa became deeply involved in obtaining and administering ketamine for the actor, despite having no medical training. He admitted buying dozens of vials, spending tens of thousands of dollars, and injecting Perry at least 27 times over several days, including three injections on the day he died.

In court filings, the government argued that he knew perfectly well what he was doing. They said doctors had already warned him about Perry's renewed drug use, and that he had twice found the actor unconscious at home and once watched him 'freeze up' and lose the ability to speak after a large ketamine dose.

At Wednesday's hearing, US District Judge Sherilyn Peace Garnett rejected any suggestion that Iwamasa was simply swept along. 'You were privy to his struggle with addiction,' she told him. 'Your conduct was reckless.'

Kenneth Iwamasa And The Ketamine Web

According to prosecutors, Iwamasa sat at the centre of two illicit supply chains. In one, Los Angeles dealer Jasveen Sangha, widely dubbed the 'Ketamine Queen', sold ketamine to Perry acquaintance Erik Fleming, who in turn supplied Iwamasa.

In the other, doctors Mark Chavez and Salvador Plasencia allegedly worked together to obtain ketamine that was then sold to Perry through his assistant.

Investigators said the group used coded language in messages, referring to bottles of ketamine as 'Dr Pepper', 'cans' and 'bots,'

Court papers describe late‑night rendezvous at the Santa Monica Pier where Iwamasa picked up vials, and a drive to a Long Beach car park so Dr Plasencia could inject Perry with ketamine in the back seat of a vehicle.

Initially, when questioned by police, Iwamasa 'concealed' the fact he had been injecting Perry, according to prosecutors. After search warrants were executed at his home, he changed his story, offering what they called a 'partial truth' before ultimately admitting full involvement. His cooperation later helped secure guilty pleas from the other four defendants.

That cooperation mattered. While the conspiracy to distribute ketamine causing death carried a maximum penalty of 15 years, prosecutors recommended 41 months, effectively cutting their own request in half. The judge followed that recommendation, also imposing two years of supervised release, a $10,000 (£7,451.75) fine and a $100 (£74.52) special assessment. He is due to report to prison on 17 July.

Kenneth Iwamasa And The Family's Fury In Court

The heaviest words in the courtroom came from Perry's family. His mother, Suzanne Morrison, wrote that Matthew trusted Kenny and that his job was to be her son's companion and guardian in the battle against addiction.

'Matthew trusted Kenny. We trusted Kenny,' his mother, Suzanne Morrison, wrote in a letter to the judge. She said his 'most important job' was to act as her son's guardian in his fight against addiction and to keep him drug free.

'Instead of protecting Matthew, he aided and abetted illegal drug taking, arranged for one source of supply, then another,' she said. 'We trusted a man without a conscience, and my son paid the price.'

Perry's sisters Caitlin and Madeline Morrison took a similarly hard line. Caitlin told the court she had 'no sympathy for Kenny Iwamasa', accusing him of either fleeing something he knew he had done or 'wilfully abandoning a vulnerable person in a dangerous situation' when he left Perry the night he died.

Madeline went further, writing that she believed Iwamasa was 'more culpable' than Sangha, the dealer who received 15 years.

Keith Morrison, Perry's stepfather, and estate executor Lisa Ferguson both argued that Iwamasa had been motivated by a desire to preserve an affluent lifestyle funded by the actor. Ferguson told the court he 'enjoyed being in complete control' of Perry's life and could have called the family at any time. She branded him 'the monster who killed' Matthew Perry, adding: 'Matthew deserved to live. You don't.'

Defence Pushback On How To See Kenneth Iwamasa

Defence lawyer Alan Eisner tried to push back against that portrayal. He told the court that his client 'idolised' Perry and compared him to Alfred Pennyworth, Batman's loyal butler.

In Eisner's account, Iwamasa was 'not someone who forced drugs on an unwilling victim' but a subordinate who felt 'incapable' of refusing a powerful employer who insisted that 'no one ever died of a ketamine overdose.'

Judge Garnett was unconvinced, interjecting at one point to say that Iwamasa was not unable but 'unwilling' to say no.

Still, the man at the centre of it all appeared to accept at least some of the blame. Addressing Perry's family from the witness stand, Iwamasa said: 'I'm so sorry to all of you. I'm just so sorry to have done illegal acts that I will forever regret. I will take that to my grave.'

Outside court, he repeated the apology and said he hoped he would serve as 'a cautionary tale' for anyone in a similar position.

With Iwamasa's sentence, all five people charged over Perry's ketamine supply have now been punished. Sangha received 15 years in April. Dr Plasencia was given 30 months in prison in December, while Dr Chavez was sentenced to eight months of home detention and three years of supervised release. Fleming received two years in prison and three years of supervision earlier this month.

Nothing about how those years of addiction and dependence unfolded can now be undone. As Perry's mother wrote in her letter to the court, for families like hers, 'closure' is not really on offer. 'Ask any mother whose child has been torn away so mercilessly,' she said. 'Nothing takes this pain away, nor will it, I am sure, for as long as I live.'

The sentencing comes nearly three years after Perry, 54, was found unresponsive in the hot tub of his Los Angeles home on 28 October 2023. An autopsy by the Los Angeles County medical examiner later ruled that he died from the 'acute effects' of ketamine, with drowning, coronary artery disease and the opioid buprenorphine listed as contributing factors.

Federal investigators went on to uncover what prosecutors described as a black‑market ketamine pipeline involving suppliers, intermediaries and two doctors, all of whom have now pleaded guilty.