The prosecution of five people involved in the death of “Friends” star Matthew Perry has come to a close. They've all pleaded guilty for their various roles in supplying the actor with ketamine, the drug that was the primary cause of his 2023 death at age 54. On Friday, his personal assistant, Kenneth Iwamasa, received more than three years in prison for facilitating his ketamine use. Two doctors, an addiction counselor and an admitted drug dealer prosecutors say was known as “The Ketamine Queen” were previously sentenced.