The wide-ranging prosecution in the death of “Friends” star Matthew Perry is coming to a close. Five people have pleaded guilty for various roles in supplying the actor with ketamine, the drug that killed him at age 54 in 2023. Three of them have been sentenced. The last two will be sentenced in the coming days. Here's a look at each person. Kenneth Iwamasa Perry’s 60-year-old longtime live-in personal assistant Kenneth Iwamasa was intimately involved in the actor’s illegal ketamine use, acting as his drug messenger and personally giving him injections — six to eight per day in the last days of his life — according to his plea agreement. “Shoot me up with a big one,” Iwamasa told authorities Perry said to him on Oct. 23, 2023. After several injections, the assistant left him at his home in the Pacific Palisades neighborhood of Los Angeles and returned to find Perry dead in his hot tub. An autopsy found the primary cause of death was the acute effects of ketamine, with drowning as a secondary cause.…