Los Angeles (CNN) -- Dr. Conrad Murray's "severely distressed" financial situation may have led him to "break the rules" in his fatal treatment of Michael Jackson, a police investigator testified Tuesday.
Los Angeles Police Detective Orlando Martinez testified in the Jackson wrongful death trial that Murray was trying to deal with the large drop in value of his Las Vegas home, unpaid taxes and child support payments for eight children with seven women.
Michael Jackson's mother and children claim AEG Live is liable for the pop icon's death because it hired, retained and supervised Murray, who worked as his personal physician as he prepared for his comeback concerts in 2009.
AEG says Murray was hired and supervised by Jackson, whom they blame for making bad choices because of his drug addiction.
One contention in the lawsuit is that the concert promoter should have known that Murray's financial stress could lead to unsafe treatments for Jackson.
Martinez, the second witness in the trial's first day of testimony, said that after interviewing Murray and after the search of Murray's car four days after Jackson's death, his "thinking at the moment was the crime was negligence."
Inside the BMW -- which belonged to Murray's sister in Texas -- he found a contract between AEG Live and Murray saying he would be paid $150,000 a month to work as Jackson's doctor, along with AEG Live President Randy Phillips' business card and cell phone number, he said.
"That's a lot of money for anyone," Martinez said. "Seeing the scene and talking to him about what he had done and how he did it raised questions."
"Focusing on the financial aspect may have been important for Dr. Murray's willingness to disregard his Hippocratic Oath for financial gain," he testified.
Murray was convicted of involuntary manslaughter and was sentenced to four years in prison. Prosecutors said Jackson death was caused by a fatal combination of the surgical anesthetic propofol and sedatives Murray gave him in a desperate effort to treat his insomnia.
Martinez said what he learned about Murray's financial troubles in the weeks after Jackson's death on June 25, 2009, led him "to opine that he may have, for this easy money -- the $150,000 a month -- may break the rules, bend the rules, to do whatever he needed to do to get paid."
His investigation revealed that Murray hadn't paid his mortgage in more than six months, his home was being foreclosed on and he had several liens for unpaid child support and tax debts, Martinez said.
Murray's Las Vegas home, which he bought for $1.6 million, was appraised at barely $1 million in 2009, he said. The Las Vegas real estate market had suffered a major decline in home values up to that date.
Judge rules: Jacksons can't watch trial without mom
The judge ordered that only one of Michael Jackson's brothers and sisters can come to court to watch the testimony at at a time -- and then only if Jackson family matriarch Katherine Jackson is present.
AEG Live lawyers argued at the start of the second day of the trial that there was "a risk in allowing any of them in the courtroom."
AEG expects to call Janet, Jermaine, Jackie, Tito, La Toya, Rebbie and Randy Jackson as witnesses in its defense. Only brother Marlon Jackson is not on the defense witness list.
AEG lawyer Marvin Putnam said in his opening statement Monday that Jackson family members will testify about their failed attempts to intervene with Michael Jackson's drug addiction and their lack of knowledge about what was happening.
The defense lawyers asked that Randy Jackson, the only one attending the trial Tuesday with his 82-year-old mother, be booted from court.
After that, Jackson lawyer Brian Panish told the judge that Katherine Jackson, who can stay in court because she is a plaintiff, needed one of her children to sit with her each day.
"He can remain, but you cannot have five in the courtroom," Los Angeles County Superior Court Judge Yvette Palazuelos said.
Because Katherine Jackson left the courtroom early to avoid gruesome testimony by a paramedic who described Jackson's death, Randy Jackson was unable to watch Tuesday's testimony.
Randy and Rebbie Jackson attended court Monday, the trial's opening day. All of the siblings attended the 2011 criminal trial of Murray at various times.
Having members of the famous entertainment family in court could influence the jury because their seats are just a few feet away from the jury box in the small Los Angeles courtroom.
Paramedic: Jackson looked like "a hospice patient"
The first witness called Tuesday was Richard Senneff, one of the Los Angeles County paramedics who responded to the 911 call from Michael Jackson's home on June 25, 2009.
Senneff mostly repeated the testimony he gave as one of the first witnesses in the Murray trial, describing how he initially "thought perhaps this was a hospice patient."
"He looked like someone who was at the end stage of a long disease process," he said.
"No, no, this just happened," Murray told him, Senneff said.
Jackson was not breathing and appeared to be dead, he said.
An AEG lawyer asked him during cross-examination if he thought Murray was not telling him the truth.
"I don't even go there," Senneff said. "I'm not worried about that."
Senneff's testimony is important to informing the jury about the circumstances of Jackson's death, but the drama that filled the Murray courtroom was not duplicated.
In fact, humor sometimes emerged. Panish even asked Senneff whether he had ever rescued a cat.
"I have not rescued a cat," Senneff, who is also a firefighter, joked. "I rescued a dog that was lying in the street."
He also shared the ironic story of the next emergency he responded to after leaving Michael Jackson at the UCLA Medical Center's emergency room.
His ambulance was called to a west Los Angeles apartment to help an elderly Russian woman, Senneff said.
"When she heard the news on TV that Michael Jackson had died, she fainted," he said. She suffered a minor head injury in her fall.
"She was just deeply emotional when we took her to the hospital," Senneff said.
Martinez will return to court Wednesday to resume his testimony, but the trial will break early so a juror can attend a funeral in the afternoon.
A medical examiner from the Los Angeles County Coroner's office is expected to take the stand Thursday. No court is scheduled for Friday.