During an occasionally testy cross-examination, the lawyer for Jackson's physician suggested that the investigator, Elissa Fleak, was sloppy in collecting evidence and writing a report the medical examiner relied on in reaching his conclusion that the death was a homicide.
“Would you agree that you made a substantial number of mistakes?” attorney Ed Chernoff asked.
“No,” Fleak replied.
She acknowledged she couldn’t explain how her thumbprint got on a syringe on Jackson's nightstand.
“I typically wear gloves. I always wear gloves at crime scenes,” she said under questioning by a prosecutor.
Prosecutors have said Murray caused Jackson's death by using the surgical anesthetic propofol as an insomnia treatment.
The defense claims that when the doctor wasn't looking, Jackson dosed himself with propofol and a handful of sedatives.
Chernoff grilled the investigator about revisions she made earlier this year to her 2009 report on Jackson's death, changes he implied were designed to corroborate the testimony of a key prosecution witness.
That witness, Alberto Alvarez, testified that he helped Murray gather up medical evidence, including an IV bag containing a bottle of propofol.
“In fact, the very first time that you noted there was a propofol bottle in an IV bag was the 29th of March 2011,” Chernoff said to Fleak.
She agreed but said she had never talked to prosecutors about their witnesses.
Asked what she knew about Alvarez's account, she said she had not been watching the trial "regularly" and had only learned his name recently: "I believe it was two days ago."
The defense attorney pressed her on the location of a pair of latex gloves, which she had written in her report were on the floor near Jackson's bed. Chernoff showed her a photo of the floor without the gloves.
Fleak insisted they were on the floor but outside camera range.
"Are you as sure about that as you are about the propofol bottle inside the bag?" Chernoff asked.
"Yes," she said.
He then showed her another photo. "What does that look like in the chair?" he asked.
"Gloves," Fleak answered.
"Do you consider that a mistake?" he continued.
"No," she said.
Under further questioning by a prosecutor, Fleak defended her work.
"Have you done your best to be as truthful and accurate as far as the role you played in this case, the observations you made and the items you recovered," Deputy Dist. Atty. David Walgren asked.
"Yes," she said.
Murray, 58, faces a maximum sentence of four years in prison if convicted of involuntary manslaughter. His trial is in its second week and is expected to conclude later this month.