Matthew Perry’s Personal Assistant, Kenneth Iwamasa, Sentenced to More Than 3 Years in Prison

In court documents, prosecutors said that when Mr. Iwamasa was initially questioned by the police, he “concealed” the fact that he had injected his boss with ketamine. A few months later, when the authorities executed search warrants at his home, he “changed his story and disclosed the partial truth,” according to prosecutors. He ultimately came clean and admitted his role in Mr. Perry’s death.

Eventually, prosecutors say, Mr. Iwamasa provided useful information about his involvement in the scheme to acquire ketamine for Mr. Perry, as well as that of others who have since pleaded guilty and been sentenced in the case.

Prosecutors have said that Mr. Iwamasa worked through two channels to obtain ketamine for Mr. Perry. In the first, a drug dealer, Jasveen Sangha, sold ketamine to an acquaintance of Mr. Perry’s, Erik Fleming, who then sold it to Mr. Iwamasa. In the second, two doctors, Mark Chavez and Salvador Plasencia, worked together to obtain ketamine to sell to Mr. Perry via Mr. Iwamasa.

An indictment said coded language was used to discuss drug deals, referring to bottles of ketamine as “Dr Pepper,” “cans” and “bots.” Mr. Iwamasa bought some of the vials after midnight at the Santa Monica Pier, according to court documents. At one point, he drove Mr. Perry to a parking lot in Long Beach, Calif., so Mr. Plasencia could inject Mr. Perry with ketamine in the back seat of the vehicle.

Mr. Chavez and Mr. Plasencia, who have both surrendered their medical licenses, were sentenced in December. Mr. Plasencia received 30 months in prison, and Mr. Chavez received three years of supervised release, including eight months of home detention. Ms. Sangha was sentenced in April to 15 years in prison. This month, Mr. Fleming was sentenced to two years.

In her letter to the court, Ms. Morrison made clear that, regardless of the sentence Mr. Iwamasa received, “closure” did not exist for her.

“Ask any mother whose child has been torn away so mercilessly,” she wrote. “Nothing takes this pain away, nor will it, I am sure, for as long as I live.”