The recent searches of Michael Jackson's personal physician's home and offices indicate that investigators have gathered significant evidence against him — likely enough to charge him with manslaughter and possibly even with murder, legal experts say.

Dr. Conrad Murray’s Las Vegas country club mansion and his office, Global Cardiovascular Associates, were searched on Tuesday, less than a week after investigators entered the cardiologist's clinic and a nearby storage facility in Houston.

Though Murray hasn't been charged with a crime, experts say the searches suggest that detectives are making progress in building a criminal case against him. The search warrants revealed that investigators were looking for evidence of manslaughter and "prescribing to an addict," among other potential charges.

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Tuesday’s searches indicate that Los Angeles investigators had enough evidence against Murray to obtain search warrants, Kenneth Padowitz, former Broward County, Fla., homicide prosecutor, told FOXNews.com.

“A search warrant has to have affidavit of probable cause, and probable cause is less than reasonable doubt — and to win a criminal case you need beyond reasonable doubt — but probable cause is sufficient to say there is evidence that indicates a potential violation of law,” Padowitz said.

“That there is sufficient evidence already accumulated that allows them to go into his office, home, look at his computer hard drive and files, that is significant.”

“This clearly indicates they’re focusing on gathering evidence for criminal charges.”

The affidavit of probable cause that accompanied the warrants would provide the details of what kind of evidence has been gathered against Murray. Those affidavits have been sealed.

The search warrant served in Houston stated that investigators were looking for “evidence of manslaughter,” but that doesn’t mean that more serious charges aren’t being considered — or that Murray’s cooperation will yield lesser charges.

Experts say it’s unlikely that Murray would have the kind of information that would be needed to cut a deal with prosecutors. Even if Murray provided information about other doctors who had given medication to Jackson, he would likely be offered a deal only if he could implicate someone more culpable in Jackson’s death than himself, experts said.

“If several other doctors gave medications improperly before Jackson’s death but if Murray gave medication, the last doctor to provide the medication is more culpable than the others,” Padowitz said.

Murray’s attorney has said the doctor is cooperating fully with the investigation.

“We’re kind of operating in a vacuum right now," Padowitz said. "We really don’t know, but if it is true that he administered this drug that’s only used in hospitals, I’m not thinking that there’s a more culpable individual out there.”

Padowitz was referring to propofol, the intravenous anesthetic that was reportedly found in Jackson's system and was reportedly present in the King of Pop's home when he died on June 25.

If prosecutors believe Murray was responsible for Jackson's death, he could be charged with second-degree murder, even though the search warrants specified the possibility of manslaughter, experts said.

Padowitz noted that it’s general practice to put the lesser crime on the search warrant.

Under California Penal Code 187, a doctor who acts with “conscious disregard” may be charged with second degree murder even if that doctor did not intend to kill the victim.

Dr. Robert M. Kahn, a clinical professor at the David Geffen School of Medicine at UCLA and expert medical consultant appointee for the Medical Board of California, said homicide charges would be filed if it were determined that propofol contributed to Jackson’s death and that Murray obtained or administered the anesthetic.

Law enforcement sources previously told FOXNews.com that Murray admitted to giving Jackson propofol shortly after midnight the day he died.

Murray’s attorney Ed Chernoff has said, “Dr. Murray didn’t prescribe or administer anything that should have killed Michael Jackson.”

Once the autopsy results are completed and the cause of Jackson’s death is reported to the police — and if the cause of death is listed as narcotics overdose — the next step will be to determine who administered the drugs in question.

But no matter how many other drugs are found in Jackson’s system, Kahn said, the responsibility is going to fall largely on Murray, who was Jackson’s attending physician.

“What are the duties of the attending physician? To be familiar with the patient’s diseases and conditions,” Kahn said. “Not knowing is not a defense.”

But criminal defense attorney and former New York prosecutor Sam Goldberg said the repeated delays in releasing the autopsy results may indicate that the case against Murray is not so cut and dry.

“I think there is a reason that autopsy results have been delayed, and not just because they want to keep it secret for longer," Goldberg said.

"It could be that the results they’ve gotten back weren’t the results they expected and now there are more questions. One question could be, ‘Is there enough here to show that the medication is what killed him?

“They want to be very, very cautious with their report because the case will likely rise or fall on the autopsy results.”

Goldberg said unclear results would weaken the case against Murray.

Experts agree that if Murray is charged with a crime, his defense will likely be that he was a licensed doctor who properly administrated medication he thought appropriate for the situation, and that something went horribly wrong. The defense could argue that administering propofol might have been outside the norm of medical practice, but it wasn't gross, wanton and reckless enough to rise to the level of a crime.

But Padowitz said that argument would fail. “It doesn’t matter if he had other medications in his system, it doesn’t matter that Michael Jackson was the one directing this. This guy is a licensed doctor with certain standards and he’ll be held responsible even if Michael Jackson was a willing participant,” he said.

“If they can tie him to administering the drug and the medical examiner indicates that drug was a part of cause of death, then this will be a serious criminal case.”

Investigators have been working with prosecutors for weeks, but they will wait until they receive the final autopsy report to present their case before the district attorney. Only then, if they have sufficient evidence, will an arrest warrant be written.

“The only thing we have to expect is that the unexpected is going to happen," Goldberg said. "That’s the way it was with Michael Jackson in life, and now, sadly, that’s how it is in his death—always mysterious, always unexpected.”