Investigators raided the home and the Las Vegas office of Michael Jackson’s personal physician last Tuesday, seizing cell phones and a computer hard drive

The seized cell phones and phone records will tell investigators about the calls made by Dr. Conrad Murray on June 25, the day Jackson died.

Detectives want to know how long it took Murray to call 911. Earlier the doctor said that paramedics arrived 30 minutes after Jackson’s death because he had a hard time contacting a security guard, couldn’t find a landline phone, and did not know the address of the pop star’s rented Holmby Hills mansion.

Investigators are also concerned that Murray had not turned over all of Jackson’s medical records. One week after Jackson’s death, at the request of investigators, Murray sent them files related to his treatment of the singer in Las Vegas, his attorney said. However, the warrants executed Tuesday made a broader demand: all records pertaining to Jackson, whether in his name or 19 potential aliases he used to conceal his identity.

The warrant authorized detectives to search for the records of prescriptions in name of the pop star and his pseudonyms including Omar Arnold, Paul Farance, Bryan Singleton, Jack London, Michael Amir Williams Muhammad, Jimmy Nicholas, Blanca Nicholas, Roselyn Muhammad, Faheem Muhammad, Frank Tyson, Fernand Diaz, Peter Madonie, Josephine Baker and Kai Chase. The name of the singer’s 12-year-old son, Prince Jackson, may also have been used as an alias.

The searches marked the second series of raids in less than a week that focused on Murray, who has been identified in court records as the target of a manslaughter investigation. Last week, authorities inspected Murray’s Houston storage unit and medical office, where the cardiologist maintained a second practice.

(via the Los Angeles Times)