The sentencing of Kenneth Iwamasa concludes the prosecution of five people in connection with the Friends star’s death.

The former personal assistant to actor Matthew Perry has been sentenced to 41 months in prison in connection with the television star’s death from a fatal dose of the hallucinogenic drug ketamine.

On Wednesday, Judge Sherilyn Garnett issued the sentence against Kenneth Iwamasa in a Los Angeles courtroom.

Iwamasa had testified, as part of a plea agreement, that he injected Perry with ketamine at the actor’s request on October 28, 2023, before leaving to run errands. He had no medical training.

When Iwamasa returned, he found Perry’s lifeless body floating in a hot tub at his home in Los Angeles’s Pacific Palisades neighbourhood. Perry was 54 years old at the time.

“I am so sorry to all of you,” Iwamasa told the court. “I’m just so sorry to have done illegal acts I will forever regret. I will take that to my grave.”

The sentencing of Iwamasa concludes the prosecution of five people alleged to have facilitated the actor’s death by helping him access the drug without proper medical supervision.

Perry, best known as the character Chandler Bing in the sitcom Friends, had been struggling with alcoholism and drug addiction for years.

Prosecutors say he had grown increasingly dependent on ketamine, which is sometimes used to help treat depression. They described Iwamasa as Perry’s “enabler and supplier”, continuing to give him injections despite troubling incidents.

Iwamasa allegedly gave Perry more than 25 shots of the drug in the days leading to his death, including three on the day he died.

Court papers state that the Friends star had asked the 61-year-old Iwamasa to “shoot me up with a big one” in his final moments.

An autopsy report found that Perry died from the “acute effects of ketamine”.

Perry’s stepfather Keith Morrison addressed the court on Wednesday to denounce Iwamasa’s actions.

“You kept injecting him with more,” Morrison said. “You could have called somebody.”

Prosecutors also successfully convicted four other people involved in Perry’s overdose death. Among them was certified drug counsellor Erik Fleming, who was sentenced to two years in prison earlier this month for acting as a middleman to help supply Perry with controlled substances.

Two doctors who allegedly profited from his addiction were also convicted and sentenced in December: Mark Chavez and Salvador Plasencia.

Chavez will serve eight months of home detention after pleading guilty to conspiracy to distribute ketamine. Plasencia — who reportedly said of Perry, “I wonder how much this moron will pay” — received a two-and-a-half-year sentence in federal prison.

A British American woman named Jasveen Sangha, who sold drugs to wealthy customers from her Los Angeles apartment, was given a lengthy sentence of 15 years in prison in a decision last month.