Updated

An expert in the powerful anesthetic blamed for Michael Jackson's death told jurors Thursday there is no way the pop star could have caused his own death by swallowing the drug, which was found in Jackson's bloodstream after his 2009 death.

Dr. Steven Shafer testified on what was expected to be the final day of the prosecution's involuntary manslaughter case against Dr. Conrad Murray. Murray, who treated Jackson for insomnia, has pleaded not guilty.

Shafer said it's impossible for any of the anesthetic that's swallowed to enter the bloodstream.

"The possibility of a direct self-injection seems extremely unlikely," Shafer added, saying it would be difficult for Jackson to have time to inject himself based on Murray's saying he was out of the singer's bedroom only for a few minutes.

It was much more likely that Murray gave Jackson a much higher dose of propofol than he told police, Shafer said.

Defense attorneys are expected to have their own propofol expert, Dr. Paul White, testify during the defense's case, which will begin on Friday.

White has also suggested that Murray probably gave Jackson more of the sedative lorazepam than he told police.

Defense lawyers have suggested throughout the trial that Jackson swallowed eight lorazepam pills without Murray's knowledge and that may have been enough to kill him.

Shafer, however, said the defense's own testing showed Jackson hadn't swallowed lorazepam pills in the four hours before his death, and the amount of the medication found in his stomach was "trivial."

Shafer also told jurors Wednesday that 17 violations by Murray each put Jackson's life at risk. Many concerned modern lifesaving equipment that Murray lacked when he gave Jackson propofol in the bedroom of his rented mansion to fight the singer's insomnia, but Shafer said among the cardiologist's worst transgressions was he put his own interests ahead of Jackson's.

He likened the cardiologist to an employee, akin to a housekeeper, who wouldn't tell his boss no.

"Saying yes is not what doctors do," he testified. "A competent doctor would know you do not do this."

Shafer, who helped write the guidelines and warnings included with every vial of propofol, repeatedly said Murray's actions were unconscionable, unethical and illegal.

He said Murray's case is unlike any he's seen before.

"We are in pharmacological never-never land here, something that was done to Michael Jackson and no one else in history to my knowledge," he told jurors.

Shafer's testimony tied together pieces of prosecution's case against Murray laid out over four weeks. He reminded jurors that Murray had bought more than four gallons of propofol to use on the singer during his employment, was on the phone in the hours before Jackson's death and delayed calling for help when he found the singer unresponsive.

"The worst disasters occur in sedation and they occur when people cut corners," Shafer said. In Jackson's case, "virtually none of the safeguards were in place."

Testimony has shown that Murray took no notes on his treatment of Jackson and didn't record his vital signs in the hours before the singer's death.

Shafer said he was testifying for the prosecution without a fee because he wants to restore public confidence in doctors who use propofol, which he called a wonderful drug when properly administered.

"I am asked every day in the operating room, `Are you going to give me the drug that killed Michael Jackson?"' Shafer said. "This is a fear that patients do not need to have."