"There's a long way to go and we hope the evidence supports -- and we believe it does -- that Dr. [Conrad] Murray was unfit for the job he was hired to do," Brian Panish told CNN. "He was financially motivated and was in serious financial straits."
Court records and credit reports presented in trial this week showed Murray was at least $1 million in debt, evidence introduced in California Superior Court in Los Angeles indicated.
The debt included delinquent taxes, lapsed student loans, unpaid child support and a defaulted mortgage, the papers indicated.
In addition, Murray's Las Vegas home had dropped $500,000 in value and was in foreclosure and his medical clinic was being evicted from an office building, other records showed.
Detective Orlando Martinez, who took the lead investigating Jackson's 2009 death, testified Murray appeared motivated by debt-fueled desperation and appeared willing to do almost anything to get $150,000 a month that Jackson promoter Anschutz Entertainment Group Live offered to pay him for taking care of Jackson.
"He may break the rules, bend the rules, do whatever he needed to do to get paid," Martinez said. "It might solve his money problems."
Jackson's 82-year-old mother, Katherine -- who is also the legal guardian of Jackson's children Prince, Paris and Blanket -- is suing AEG Live for the pop singer's death.
The lawsuit alleges AEG Live was negligent in hiring Murray to care for the singer while he rehearsed for the concerts.
AEG Live lawyers argue Jackson was treated by Murray before the shows were even planned. They say Jackson chose and controlled Murray and was addicted to prescription drugs long before he agreed to do the concerts.
AEG Live sponsored a planned series of 50 Jackson "This Is It" comeback concerts that were scheduled for London's O2 Arena from July 2009 through March 2010.
Jackson died June 25, 2009, at age 50, less than three weeks before the first scheduled concert.
Murray, who isn't involved in the wrongful-death lawsuit, was convicted of involuntary manslaughter in 2011 for giving Jackson a fatal dose of the anesthetic propofol to help him sleep. He is completing a four-year prison sentence.
Katherine Jackson, who filed the wrongful-death lawsuit after Murray's conviction, seeks damages of equivalent to the amount of money Jackson would have earned over the course of his remaining lifetime if he had not died in 2009, estimated at $40 billion.
On Thursday, Martinez testified under cross-examination from AEG Live lawyers Katherine Jackson suspected her son had become addicted to back-pain medicine but the singer denied he had a drug problem.
"Mrs. Jackson said the family tried to help him but he would have nothing to do with it," Martinez said.
The trial is to resume Monday, when a coroner toxicologist is to testify about the drugs found in Jackson's body after his autopsy.
The doctor who conducted the autopsy is to follow on the witness stand.