Matthew Perry's Sister Draws Clear Line: No Sympathy for Assistant Kenneth Iwamasa

Grief does strange things to families. It crystallizes blame. It sharpens lines between right and wrong that might’ve seemed blurry under different circumstances. And sometimes, it forces loved ones to say things publicly that feel necessary to say—even when it hurts.

That’s where we find Caitlin Morrison, Matthew Perry’s sister, ahead of her brother’s assistant Kenneth Iwamasa’s sentencing. In a letter submitted to the court, Morrison made her position unmistakable: while she can find sympathy for many people—even the drug suppliers who bear responsibility for Matthew’s death—she has none for Iwamasa. Not a drop.

The weight of her words stems from what Iwamasa allegedly did. He’s accused of securing Matthew’s illegally obtained ketamine and, most damning, of injecting him on the day he died on October 28, 2023. But it’s not just the act itself that Morrison seems unable to forgive. It’s what came after. According to her letter, Iwamasa didn’t just make a terrible mistake and own it. He allegedly wove a story to cover his tracks, hounded the grieving family, and tried to extract money from Matthew’s mother—whose son was lost. That’s the breach of trust that appears unforgivable to Morrison.

What makes her letter compelling is the nuance beneath the conviction. She acknowledges she wasn’t there that night. She admits she can’t read Iwamasa’s mind or know whether the lethal dose was intentional or catastrophic accident. She even extends a moment of understanding—saying she could see herself potentially making a life-or-death mistake and wanting to run from what happened. But that same empathy evaporates when she thinks about the cover-up, the exploitation of a mother’s grief, the apparent self-preservation at the expense of honesty.

“If you ask me, he could use a good long time to think about it,”Morrison concluded—a statement that doubles as both plea to the judge and final word from a sister who’s watched her brother become a cautionary tale about the dangers of unmonitored substance use and the people who enable it. Whether Iwamasa’s sentencing reflects Morrison’s wishes remains to be seen. But her letter ensures the court understands exactly what Matthew Perry’s family believes justice should look like in this case.