Sources: Jackson investigation nearing end

LOS ANGELES, Sept. 16 (UPI) -- The police investigation into Michael Jackson's June 25 death in Los Angeles is nearly finished, law enforcement sources told TMZ.

Jackson's death at the age of 50 was declared a homicide after lethal levels of the anesthesia propofol were found in his system. Conrad Murray, the doctor who administered the drug to Jackson, has been under investigation, but no criminal charges have been brought against him.

TMZ reported Wednesday that the case is expected to be presented to the Los Angeles County district attorney in three to four weeks and Murray remains the focus of the probe.

The Los Angeles Police Department reportedly is waiting for several medical experts to submit their opinions before they can compile their own findings and pass them on to the prosecutors' office, which will decide whether criminal charges should be filed.