Matthew Perry's Assistant Sentenced to Prison for Fatal Ketamine Injections

Trusted Caregiver Becomes Enabler

The man who was supposed to be Matthew Perry's guardian in his battle against addiction instead became his enabler and, ultimately, his executioner. Kenneth Iwamasa, Perry's live-in personal assistant, was sentenced Wednesday to three years and five months in federal prison for administering the dose of ketamine that killed the "Friends" star in October 2023 . The 61-year-old also received a $10,000 fine and represents the fifth and final defendant sentenced in connection with Perry's death.

Perry had hired Iwamasa in 2022, paying him $150,000 a year to live at his Los Angeles home and coordinate his medical care . What began as legitimate assistance quickly transformed into something far more sinister. While Perry was legally receiving ketamine treatments for depression, he wanted more than his doctor would prescribe . According to Iwamasa's plea agreement, he bought off-the-books ketamine from doctor Salvador Plasencia, who taught him how to inject it .

Victim impact statements from Perry's sisters described Iwamasa as a man who "left him in a hot tub to die" . Perhaps most painfully for the family, "Kenny even spoke at Matthew's funeral," wrote sister Madeline Morrison. "The person responsible for my brother's death stood up and addressed the people who loved him most" .

A Pattern of Dangerous Escalation

Iwamasa witnessed clear warning signs that Perry was in danger, finding the actor unconscious at his residence on at least two occasions and seeing him freeze up and become unable to talk or move after ketamine injections . Despite doctor Plasencia stating "Let's not do that again" after one particularly dangerous reaction, Iwamasa had already begun arranging for a steady supply from street dealers .

In the final days of Perry's life, Iwamasa was injecting him six to eight times per day . In October 2023 alone, he purchased 51 vials of ketamine over 11 days . On October 28, 2023, Iwamasa injected Perry with at least three shots of ketamine, which caused Perry's death .

The prosecution revealed a web of enablers surrounding Perry's addiction. Four other defendants were previously sentenced, including "Ketamine Queen" Jasveen Sangha who received 15 years in prison , along with two doctors and a drug broker who facilitated the illegal ketamine distribution.

Cover-Up and Consequences

When authorities arrived, Iwamasa initially lied to police, omitting ketamine from the list of medications Perry was using and providing a chronology that concealed the ketamine injections he had administered . He also destroyed evidence related to Perry's ketamine use, cleaning up bottles and syringes and telling accomplice Erik Fleming that he had "deleted everything" .

"You were privy to his struggle with addiction," Judge Sherilyn Peace Garnett said before sentencing. "Your conduct was reckless, not just on the day of his death but in the days leading up to his death" . Iwamasa became prosecutors' most important witness after pleading guilty in August 2024 to conspiracy to distribute ketamine resulting in death .

This case highlights the dangerous intersection of celebrity, addiction, and enablement. Perry's death serves as a stark reminder that those entrusted with protecting vulnerable individuals can become their greatest threat when financial incentives and power dynamics override moral obligations. As Perry's mother noted in her victim impact statement, Iwamasa "shot the drugs into Matthew's body, though he was not in the least qualified" to do so, transforming a trusted relationship into a fatal betrayal.