LOS ANGELES -- The personal physician from Houston who tried to revive a dying Michael Jackson has been named as the target of a manslaughter probe into the singer's death.

A search warrant filed Thursday allowed authorities to seek "property or items constituting evidence of the offense of manslaughter that tend to show that Dr. Conrad Murray committed the said criminal offense."

The warrant was filed a day after agents seized items from the physician's Houston clinic, the Armstrong Medical Clinic in the 6600 block of West Montgomery Road, and a rented storage unit on 18th Street.

Police and agents went through the office for about 2½ hours.

The Houston storage facility manager said Murray's employees removed boxes stored at his unit the same day Jackson died.

Sue Lyon said Murray rented the storage room in April.

On the morning of June 25, two women she identified as Murray's clinic managers left with three to five small boxes three hours before Murray called 911 in Los Angeles to report that Jackson's heart had stopped.

Lyon said she does not know what was in the boxes.

Murray, 51, was with Jackson as he died and has been a key figure in the monthlong investigation since the beginning. The search of his clinic indicated authorities were focusing on him, but the warrant language made it clear he's the target.

The court documents detailed items seized by federal drug agents and Los Angeles police. Among them were 27 tablets of the weight loss drug phentermine, a tablet of the muscle relaxant clonazepam, two computer hard drives, e-mails and a controlled substance registration.

Murray's lawyer, Edward Chernoff, confirmed a search warrant had been executed and that none of the items seized had previously been requested by authorities, but did not comment further.

Murray was hired as Jackson's personal physician just weeks before he died. He was in Jackson's rented Los Angeles mansion when the pop star was found unconscious the morning of June 25 and tried unsuccessfully to revive him.

Murray, a cardiologist, is licensed to practice in California, Texas and Nevada. Records show he has had no disciplinary actions taken against him, though one item seized by investigators is a suspension notice from a Houston hospital. No details are provided.

The Los Angeles County coroner's office was not expected to make an official determination of what killed Jackson until at least next week, and investigators this week were reviewing medical records taken from the offices of other doctors in the probe.

Assistant Chief Coroner Ed Winter said Thursday he had sought information from "seven or eight" doctors and Murray is the only one he has yet to talk to.

Winter said Chernoff had offered to speak with the coroner Friday but without Murray present.

"We don't want to talk to the attorney, we want to talk to" Murray, Winter said.

Chernoff issued a brief statement in response, saying Winter had not made any requests to interview his client.

The powerful anesthetic propofol has emerged an important part of the investigation. Doses of it were found in Jackson's mansion, according to a person with knowledge of the investigation who is not authorized to speak publicly. The drug was not among the items seized under the search warrant.