Operatives of the Los Angeles Police Department and federal drug agents raided the office of Michael Jackson’s personal physician in Houston last Wednesday.

Armed with a search warrant saying that the police are investigating Michael Jackson’s death as manslaughter, officers seized documents and computer files from Dr. Conrad Murray. The warrant, which many observers see as the strongest indication that authorities are investigating Jackson’s death as a crime, was signed by a Harris County District Court judge.

In a statement, the doctor’s lawyer said, “The search warrant authorized law enforcement to search for and seize items, including documents they believed constituted evidence of the offense of manslaughter.”

Murray was not present when officers searched the Acres Home Heart and Vascular Institute, a cardiology clinic he opened in 2006. The Los Angeles Times reported that investigators took the doctor’s Rolodex, business cards, information about his use of FedEx, e-mails he had received from a former employee, receipts for a storage unit and cell phone and pamphlets advertising a nearby sleep clinic.

The 51-year-old cardiologist opened the Houston clinic three years ago in honor of his father, a physician who had worked in the poor, predominantly black neighborhood for decades. He was paid $150,000 for being the personal physician of Jackson.