On the day Matthew Perry died, his live-in personal assistant gave him his first ketamine shot of the morning around 8:30. About four hours later, while Perry watched a movie at his home in Los Angeles, the assistant gave him another injection.

About 40 minutes later, Perry wanted another shot, the assistant, Kenneth Iwamasa, recalled in a plea agreement that he signed.

“Shoot me up with a big one,” Perry told Iwamasa, according to the agreement, and asked him to prepare his hot tub.

So Iwamasa filled a syringe with ketamine, gave his boss a third shot and left the house to run some errands, according to court papers. When he returned, he found Perry face down in the water, dead.

Iwamasa is one of five people charged with a conspiracy to distribute ketamine, a powerful anesthetic, to Perry, authorities in California said last week. The other defendants are two doctors, a woman accused of being a dealer, and an acquaintance who pleaded guilty to acting as a middleman.

Perry, a beloved figure who rose to fame playing Chandler Bing on the sitcom “Friends,” had long struggled with addiction. Court papers filed in the case shed light on the desperate weeks leading up to Perry’s death Oct. 28 at age 54.

In his last days, law enforcement officials said, he appeared to become increasingly reliant on ketamine and eager to find illegal sources of it after doctors at a local clinic had refused to increase his dosage.

There were warning signs that it was dangerous. The court papers refer to several instances in which Perry experienced adverse effects from the drug, including when his assistant found him unconscious at his home and observed him losing the ability to speak or move after a large dose.

In the indictment, which followed a seven-month investigation and grand jury proceedings, prosecutors accused several of the defendants of enabling Perry’s ketamine use despite being aware of his history of drug abuse and addiction, and his attempts to stay sober.

This account of Perry’s last days was drawn from the indictment and from the plea agreements reached by Iwamasa and two of the other defendants. Efforts to reach the defendants were unsuccessful; on Thursday, Dr. Salvador Plasencia and Jasveen Sangha, whose trials are scheduled for October, pleaded not guilty.

As Perry’s personal assistant, Iwamasa was tasked with coordinating his doctor’s appointments and making sure he took the proper medication.

Ketamine, a strong anesthetic with psychedelic properties, is sometimes used as an alternative therapy for depression, anxiety and other mental health problems. It is also used recreationally.

Perry had earlier pursued ketamine therapy, law enforcement officials said. In September, Perry asked Iwamasa to procure him ketamine illegally, according to the plea agreement.

Iwamasa was introduced to Plasencia as he sought the drugs.

At one point Plasencia mused on the money he stood to make with a friend, Dr. Mark Chavez.

“I wonder how much this moron will pay,” Plasencia texted Chavez, who prosecutors said later supplied him 22 vials of ketamine and ketamine lozenges obtained through a fraudulent prescription for the drug. “Lets find out.”

Chavez agreed to plead guilty to one count of conspiracy to distribute ketamine.

Plasencia, known as “Dr. P.,” soon instructed Iwamasa on how and where to inject ketamine into Perry’s body.

“Found the sweet spot but trying different places led to running out,” Iwamasa texted Plasencia on Oct. 4, according to court papers.

Over the next several days, Iwamasa’s requests for ketamine became more urgent.

“I just ran out,” Iwamasa texted the doctor, who replied he had two vials to sell him if the assistant could meet him in Santa Monica.

That week, Plasencia met Perry and his assistant in a parking lot near an aquarium in Long Beach. He injected the actor in the back seat of the car, passing along multiple additional vials. Perry would pay at least $55,000 to Plasencia for ketamine over about a month, according to court papers.

The actor and his assistant were beginning to look for additional sources to keep up their supply of the drug.

Perry began communicating with a man named Erik Fleming, with whom he shared a mutual friend. Fleming, who later agreed to cooperate with law enforcement, texted Perry on Oct. 10 that he could sell him ketamine at a “good price,” as long as he received a tip for brokering the deal.

The next day, Fleming showed Iwamasa screenshots of his communications with his source, a woman named Jasveen Sangha, whom Fleming described as working with “high-end” clients and celebrities. “If it were not great stuff she’d lose her business,” he wrote.

On the same day that Perry received a legal ketamine infusion treatment from another doctor at a medical office, Plasencia visited Perry’s home and administered a “large dose” of ketamine, according to Iwamasa’s account to law enforcement. Perry froze up, was unable to speak or move, and experienced a spike in blood pressure; Iwamasa and the doctor struggled to move him onto a couch.

Plasencia “stated something to the effect of, ‘let’s not do that again,’ ” the court papers said. But he continued to offer more ketamine.

The next day, Fleming delivered a sample vial of ketamine to Perry’s home for $180. Satisfied with the drug, Iwamasa asked for more. Fleming delivered 25 vials for $6,000, including $500 for his own work, on Oct. 14.

Ten days later, Fleming delivered another 25 vials, along with ketamine lollipops that Sangha included as a bonus.

Iwamasa and Fleming agreed to sign plea agreements, giving officials a window into Perry’s final days. Chavez began cooperating with law enforcement as well. Iwamasa faces up to 15 years in prison; Fleming, up to 25 years; Chavez, up to a decade.

In the final days leading up to the actor’s death, Iwamasa injected Perry six to eight times a day. At least twice, he found Perry unconscious at his home, the assistant told law enforcement.

On Oct. 28, after finding Perry dead, Iwamasa cleaned up the bottles and syringes left in the house, according to Fleming’s account of a conversation they later had.

That day Sangha deleted her text messages with Fleming from the app Signal and instructed him to “delete all our messages,” according to law enforcement officials.

In December, the Los Angeles County medical examiner’s office said Perry had died of the “acute effects” of ketamine. The autopsy report noted that the level of ketamine found in his blood was equivalent to the amount used for general anesthesia.