Matthew Perry's assistant accused of destroying evidence of actor's ketamine abuse ahead of sentencing

Matthew Perry's one-time assistant Kenneth Iwamasa is accused of destroying evidence of the late actor's drug use in the wake of his death more than two years ago.

Iwamasa sought to cover up proof of Perry's drug use one hour after the death of the Friends actor at 54 on October 29, 2023 at his Pacific Palisades, California home, according to a recent filing from federal prosecutors reviewed by TMZ. 

It comes prior to Iwamasa's sentencing Wednesday, as prosecutors are asking for a sentence of 41 months after the assistant - who faced up to 15 years in prison - cut a plea deal in August of 2024.

Iwamasa pleaded guilty to a count of conspiracy to distribute ketamine causing death, after officials with the Department of Justice said he 'repeatedly' and 'without medical training,' shot the actor up with lethal amounts of ketamine. 

After Perry, who played Chandler Bing on the NBC series, was found dead face down in his jacuzzi, Iwamasa got to work destroying hard copies and digital evidence involving the actor's use of ketamine, federal authorities said in their latest filing.

Prosecutors said Iwamasa told another person to get rid of proof of the network of individuals that set up a supply chain of drugs for the actor's personal use.

Iwamasa, a native of Toluca Lake, California, was untruthful on multiple occasions once the investigation into the actor's passing commenced, prosecutors said in the filing.

Iwamasa tried to conceal that he had personally administered several shots of ketamine to Perry in the hours prior to his passing, according to prosecutors.

The assistant also falsely claimed Perry was responsible for hiding the bottles of ketamine in the home, prosecutors said in the legal filing.

A person who was called 'B.M.' was ordered by Iwamasa to round up the physical evidence of the actor's drug abuse - including ketamine vials and syringes - and get rid of it immediately, according to prosecutors.

Iwamasa also told an associate that other items - such as a written prescription for ketamine, and a note linking Dr. Salvador Plasencia to Perry's drug network - also had to be shredded, according to the filing.

Iwamasa informed Erik Fleming, another associate in the network, that he 'cleaned up the scene' of the actor's home after he died, according to prosecutors.

Prosecutors said Iwamasa told Fleming that he destroyed physical evidence, changed Perry's digital passwords and 'deleted everything' from computers as he sought to cover up evidence of the star's ketamine use.

Iwamasa betrayed both the actor and his family by failing to serve as a handler for the addiction-prone actor, instead enabling his worse impulses, according to prosecutors.

Perry’s sisters Caitlin and Madeline Morrison were critical of Iwamasa in statements submit to U.S. District Judge Sherilyn Garnett in a May 20 court filing reviewed by People.

'It is difficult to put into words the sense of betrayal I felt when I found out what Kenny had done,' Madeline Morrison said. 'In many ways, it felt like my brother died all over again. 

'Everything I believed about the day he died - everything Kenny told us - was a lie.'

She said that 'the idea that someone my brother considered family could betray him in such an unimaginable way is something I never could have conceived.'

Madeline said that Iwamasa's behavior was suspicious in the wake of her brother's passing.

'A few days after Matthew died, my sister and I went to choose clothes for him to be buried in - one of the most surreal and heartbreaking experiences of my life,' Madeline said. 'I remember how manic and unsettled Kenny seemed.

'He repeatedly volunteered his version of events without being asked, as if he were being interviewed rather than mourning a friend.'

She added, 'In reality he was trying to distract us from the truth: that he had injected my brother with a lethal dose of ketamine and left him in a hot tub to die.'

Madeline noted that Iwamasa 'even spoke at Matthew's funeral,' effectively tainting the family's 'final memories of saying goodbye' after learning about the role he played in the actor's tragic end.

'The person responsible for my brother's death stood up and addressed the people who loved him most,' Madeline said. 'That is like a cruel joke I still struggle with.'

Caitlin Morrison said she had 'no sympathy' for Iwamasa ahead of his sentencing.

'I cannot read Kenny's thoughts,' she said. 'I will never know if the lethal dose of ketamine was only lethal by accident.

'But I know that when Kenny left the house, he was doing one of two things. He was either escaping from something he knew he had done or he was willfully abandoning a vulnerable person in a dangerous situation.'