Fifteen cars full of Los Angeles detectives and federal drug agents arrived Wednesday morning at the Houston clinic of Michael Jackson's doctor after obtaining a warrant based on preliminary autopsy results that indicate a drug overdose linked to Jackson's demise. Dr. Conrad Murray is the last doctor to have seen Jackson alive and is suspected of administering the drug in question, Propofol, which is usually only used in hospitals. Murray and his lawyer aren't saying whether the drug was administered, but say they're eager to close the case. "The coroner wants to clear up the cause of death, we share that goal," explained Murray's lawyer. The site of the raid is located in the Armstrong Medical Clinic, owned by a doctor whose DEA license was revoked in 2005 for "over prescribing," according to officials.