TIMELINE: Michael Jackson's Final Days

June 23, 2010— -- It was to be Michael Jackson's first concert series in a dozen years, billed as one of the greatest comebacks of all time. When Jackson himself arrived in London to announce his tour, no one dreamed that in less than four months, the King of Pop would be dead.

Jackson's sudden, unexpected death raised suspicions and questions that still linger today, a year after his death.

As the entertainer's personal physician awaits trial on manslaughter charges for allegedly administering the overdose of intravenous and prescription medications that killed him, those who knew Jackson and spent time with him in the months before his death disagree about his state of mind.

Watch the full 2-hour special, "Michael Jackson: After Life," Friday on "20/20" at 9 p.m. ET.

Some say Jackson was happier than he'd been in years. Meanwhile, others paint a picture of a man whose health was unraveling, worsened by a severe addiction to prescription drugs, including the intravenous anesthetic propoful, reportedly to combat chronic insomnia.

Propofol is normally only used in hospital settings with a trained anesthesiologist who monitors the patient's heart rate and breathing continually while they are unconscious during surgery. Propofol can trigger cardio-respiratory effects that are potentially fatal.

"This is way off the chart,'' said Vesna Maras, a former Los Angeles deputy district attorney. "This, this is not even FDA-approved for insomnia. It is not a sleep aid. You look at what is this stuff? It's an anesthetic agent that is used to put somebody under, basically knock them unconscious. So in other words, it would be like using a hammer to kill an ant."

What follows is some of what is known about the final days and hours of Jackson's life.

Final Days: Concert Preparation, Insomnia and Stress

The documentary "This is It," just released on DVD, provides a roadmap of Jackson's last days as he prepared for his tour.

At first glance he seemed confident and in control.

"I gotta cue that ... that shouldn't trigger on its own,'' said Jackson, still lithe and youthful at 50, in footage of a concert rehearsal.

A famous perfectionist, Jackson "was not going to settle,'' said Travis Payne, the show's choreographer. "He wouldn't allow any of us to settle."

"I think he was happier than he had been in years."

Jackson's former manager, Frank DiLeo, told ABC News: "I saw a guy that wanted to perform. But he wanted to do it right. And he was strong enough. He was working out every day. If he wasn't healthy, if there was something wrong, I would have stopped him. No. There was nothing to stop."

But DiLeo and other concert executives were concerned that Jackson was losing weight and not sleeping. "He said he wasn't sleeping," said DiLeo. "And I said to him, 'Well, what seems to be the problem?' 'Well, I'm just excited. You know, I'm all wound up.'"

"We were concerned," said Randy Phillips, the show's promoter. "I hired someone whose job it was to be sure that he eats... [Director Kenny Ortega] would cut Jackson's chicken breast for him, and say, 'Eat! Eat!'"

"Find Me an Anesthesiologist"

On Easter 2009, registered nurse Cherilyn Lee said Jackson had called her, frantically begging for propofol, the intravenous anesthetic, saying he needed it to sleep.

"He said, 'Find me an anesthesiologist. I don't care how much money they want,'" Lee recounted.

Lee said she warned Jackson. "Michael...I love you as family," she said she told him. "I would not give this to anyone. This is not a safe medicine. Please don't take this."

"And I said, 'The problem with you telling me you want to be "knocked out"' -- those are his word,-- 'is that you might not wake up the next morning.' I mean the last end result of this is death. I said, 'You don't want to do this.' He said, 'No, my doctor said it's safe. It works quick and it's safe. As long as somebody is here to monitor me and wake me up, I'm going to be OK.'"

June 21, 2009: Jackson, Wasting Away, Begged for his Drug of Choice.

On June 21, Lee received a foreboding call from a Jackson aide. Lee said Jackson's aide told her the singer needed to see her right away.

"I could hear Michael in the background: 'Tell her. Tell her that one side of my body is hot, is hot, and one side of my body is cold, it's very cold,'" Lee said. "And I said, 'tell him he needs to go to the hospital.'

"I knew that somebody had given him something that hit that central nervous system," she said. "He was in trouble."

The concert executives were concerned that Jackson was losing weight and not sleeping. "We were concerned," said Randy Phillips, the show's promoter. "I hired someone whose job it was to be sure that he eats... [Director Kenny Ortega] would cut Jackson's chicken breast for him, and say, 'Eat! Eat!'"

June 22, 2009: Cutting Back on Propofol

"We saw Michael Jackson deteriorating,'' Harvey Levin of TMZ said. "He looked increasingly frail. It was pretty clear, something was wrong.

Several times a week during rehearsals for "This Is It," Jackson visited the Beverly Hills office of his longtime dermatologist and close friend Dr. Arnold Klein, staying for hours at a time, reportedly to sleep.

"He was not in terrible pain when I saw him,'' Klein said. "He danced in the office, and he danced for my patients."

But Jackson was also in the care of another physician, Dr. Conrad Murray, a Las Vegas and Houston cardiologist. Murray was the singer's personal physician and had been treating him for insomnia. Jackson had insisted the concert promoters hire Murray to care for him during "This Is It" -- paying him $150,000 a month.

According to police documents, on June 22, Murray said he tried to wean Jackson from propofol, giving him half the dose he normally would, just 25 mg, along with another sedative and an anti-anxiety drug. It was enough to put Jackson to sleep.

June 23, 2009: "Amazing" Rehearsal, Followed by Sweet Sleep.

Dancers from the show say Jackson was in great form for rehearsal. "He was so full out and incredible on stage,'' said Tyne Stecklein. "He was amazing."

That night, Murray says he gave Jackson only Ativan and Versed, but no propofol. Jackson fell asleep.

June 24, 2009: Final Rehearsal: Goose Bumps

Jackson's final rehearsal, which stretched into the next day, went well and the singer left "excited and ecstatic,'' said Payne, the choreographer.

"We all had goose bumps,'' said Phillips, the promoter. "I had never seen such exultation in the cast and crew."

When they left rehearsal around 12:30 that morning, Phillips described how Jackson "put his arm around me, and he said to me in that kinda soft, lilting voice of his, he said, 'Thank you for getting me here. I got it now, I know I can do this. I'll take it from here.'"

June 25, 2009: His last 12 hours: Sleep Eludes the King of Pop.

12:30 a.m.: Michael Jackson's black Escalade returned to his rented mansion near Beverly Hills around 12:30 a.m.

In his second-floor bedroom, the heat was on high and a fire burned in the fireplace. Despite the warm Los Angeles June weather, Jackson was cold. Murray, his physician, arrived around 1:00 a.m. to help Jackson fall asleep.

Around 1:30 a.m.: Jackson received a 10 milligram tablet of Valium from Murray to help him sleep.

Around 2:00 a.m.: Murray injected Jackson with 2 milligrams of the sedative Ativan, delivered by a slow push through an IV.

Around 3 a.m.: Jackson received another injection, 2 milligrams of another sedative, Versed. But he still could not sleep.

About 5 a.m.: Jackson was still awake. Murray administered more Ativan. But, as the sun rose over Los Angeles, Jackson repeatedly asked for his "milk," the name he used for the milky-white drug propofol.

Murray told police he refused Jackson's request.

Approximately 7:30 a.m.: Jackson received two more milligrams of Versed. But he still could not sleep.

About 10:40 a.m. The doctor finally gave in to Jackson's demands, according to a police affidavit, administering a relatively small dose -- 25 milligrams -- of propofol, into his IV. All the while, Murray told investigators, he continued to monitor Jackson's heart rate and breathing with a pulse oximeter.

Just after the sedative entered Jackson's bloodstream, his eyes shut, his breathing slowed, and he fell sound asleep.

Michael Jackson: 911

About 10:50 a.m.: Police say Murray told them he took a break for two fateful minutes to go to the bathroom, and when he returned, he told police, Jackson had stopped breathing.

"The doctor rushed over to him, felt his body to see if he was warm," said Murray's attorney, Ed Chernoff, of when Murray found Jackson not breathing. "He was, uh, looked for a pulse, found a weak pulse and started performing CPR." Chernoff said Murray was simultaneously trying to perform CPR and call 911.

But 911 was not called until nearly 90 minutes later. Instead, cell phone records show that for 47 minutes -- after Murray said Jackson stopped breathing -- Murray made three calls: one at 11:18 a.m., to his Vegas medical clinic, for approximately 32 minutes; one to a patient whom he called to talk about test results; and, at 11:51 a.m., to a friend in Houston, for an 11-minute phone call. The friend has said that a few minutes into the call, Murray dropped the phone, and the friend could hear him administering CPR to Jackson.

However, Chernoff issued a statement Aug. 24 claiming the police have the timeline all wrong. The statement said, in part: "Much of what was in the search warrant affidavit is factual. However, unfortunately, much is police theory... Dr. Murray simply never told investigators that he found Michael Jackson at 11:00 a.m. not breathing. He also never said that he waited a mere ten minutes before leaving to make several phone calls. In fact, Dr. Murray never said that he left Michael Jackson's room to make phone calls at all. "

According to Chernoff, Murray didn't call 911 himself because he didn't know the address of the house. Then, around noon, he ran down the stairs to the kitchen for help. Chef Kai Chase was making lunch and heard the doctor in a panic, calling for Jackson's oldest son, Prince, and asking for help.

12:12 p.m.: Murray called Jackson's personal assistant, Michael Amir Williams, and left a message "telling him to come quick," according to a police statement made by Williams. Thomas Watkins, a crime reporter for The Associated Press in Los Angeles, exclusively obtained Williams' police statement, along with a statement made by security guard Alberto Alvarez and other eyewitnesses in the house.

Shortly after noon, Murray also ran down the stairs to the kitchen for help. Chef Kai Chase was making lunch and heard the doctor in a panic, calling for Jackson's oldest son, Prince, and asking for help.

According to Alvarez's police statement, he ran upstairs to Jackson's bedroom, where the entertainer was lying on his back, with his arms extended outward from his body. His eyes and mouth were open, according to Watkins, who obtained Alvarez's official statement to the Los Angeles police.

Dr. Murray was on one side of the bed, performing CPR on Jackson with one hand. Two of Jackson's children, Paris and Prince, walked into the bedroom. Alvarez quickly escorted them out and they ran to the cook Kai Chase's waiting arms.

"We stood in a circle and we held hands together, and, you know, we were crying 'cause we don't know. And you feel helpless," said Chase.

Upon returning to the bedroom, Alvarez asked Murray what happened. According to Watkins, Alvarez said Murray replied, "He had a bad reaction, he had a bad reaction."

The security guard told authorities that Murray then grabbed a few vials of medicine, saying, "Put these in the bag." All the while, Alvarez said in Watkins' account, Murray was continuing CPR on Jackson with one hand. He told Alvarez to remove one of the IV bags, containing a white substance, the propofol, and place it in the doctor's blue bag, Watkins says. He then told Alvarez to dial 911.

12:21 p.m.: Alvarez calls 911.

Dispatcher: 911 what is your emergency?

Alvarez: we have a gentleman here that needs help and he stopped breathing. He's not breathing and we need to -- we're trying to pump him but he's not...

Dispatcher: He's not breathing?...and he's not conscious either?

Alvarez: He's not conscious sir.

Dispatcher: OK, all right... is he on the floor? Where is he at right now?

'He's Not Responding'

Alvarez: He's on the bed sir, he's on ...

Dispatcher: OK, let's get him on the floor.

Dispatcher: Did anybody see him?

Alvarez: Yes, we have a personal doctor here with him sir.

Dispatcher: Oh, you have a doctor there?

Alvarez: Yes, but he's not responding to anything. No, he's not responding to CPR or anything.

According to Alvarez's statement to police, obtained by AP reporter Tom Watkins, Alvarez saw no signs of life, but Murray directed him to compress Jackson's chest while the doctor attempted mouth-to-mouth resuscitation.

Murray then confessed that he'd never performed CPR before, Alvarez told police.

Approximately 12:27 p.m.: An ambulance and fire truck arrived at Jackson's home, followed closely by paparazzi . One photographer looked into an emergency vehicle and spotted the call screen, which read, "50-year-old male not breathing."

"That told us, this is probably Michael,'' said Ben Evenstad, who runs National Photo Group.

According to a paramedics' report, when they arrived, Murray was performing CPR on Jackson, who was lying on the floor with an IV in his leg.

Just after 1 p.m.: After approximately 4o minutes at Jackson's home, the paramedics raced to the hospital with the singer's lifeless body. According to TMZ's Harvey Levin, the paramedics knew he was dead but Murray insisted he go to the hospital. Jackson's children followed in one Cadillac Escalade, his bodyguards in another.

1:13 p.m.: Jackson arrived at UCLA Medical Center in Westwood, and Murray met with the physician in charge of the emergency department. Murray did not disclose that he gave Jackson propofol that day, only admitting to giving him two separate doses of Lorazepam, according to the police affidavit.

At the hospital, the bodyguards who protected Jackson in life, tried to protect his privacy in death, lashing out at paparazzi. In a video taken by National Photo Group outside of the hospital, the bodyguards can be seen opening up their jackets so Jackson's body cannot be seen entering the hospital.

News of Jackson's death spread like lightening. La Toya Jackson's father called her to say she must get to the hospital quickly. When she arrived, fans were already assembling.

"I went into the room, and there's my mother sitting down. And there are the kids, all three of them on her, sitting on her lap just crying as loud as they could. They were just crying uncontrollably. And there I was, screaming and crying."

2:26 p.m.: Jackson was pronounced dead at UCLA Medical Center. Many fans and media were gathered outside the hospital.

Soon the world would learn of Michael Jackson's death. "My brother, the legendary King of Pop, Michael Jackson, passed away on Thursday, June 25, 2009 at 2:26 p.m.,'' said Jermaine Jackson, his brother, at a press conference. "It is believed he suffered cardiac arrest in his home."

"I just couldn't believe it,'' said Janet Jackson, in an interview with ABC's Robin Roberts last November. "It just didn't ring true to me. It felt like a dream."

Aug. 27, 2009: The Los Angeles coroner's office ruled Michael Jackson's death a homicide. The cause of death was "acute propofol intoxication with benzodiazepine effect," according to the coroner's report.

Feb. 8, 2010: Murray was charged with involuntary manslaughter and pleads "not guilty." He is currently awaiting trial.

One year later, Jackson's family and fans continue to mourn the loss of the music legend.

"I simply want justice,'' said La Toya Jackson, in an interview with Barbara Walters. "What's ever right. In the court of law. I want justice. They've taken a life away from us, from all of us."

Watch the full 2-hour special, "Michael Jackson: After Life," Friday on "20/20" at 9 p.m. ET.