Deputy District Attorney David Walgren speaks in rebuttal of the defense's closing arguments as defense attorney Ed Chernoff (3rd L) listens during Dr. Conrad Murray's (2nd L) involuntary manslaughter trial in the death pop star Michael Jackson in Los Angeles November 3, 2011.[Photo/Agencies]

LOS ANGELES - The jury in the trial of the doctor accused of involuntary manslaughter in the 2009 death of pop star Michael Jackson ended its first day of deliberation on Friday with no verdict being announced.

The jury of seven men and five women will return on Monday for more discussion on the guilt or innocence of Dr Conrad Murray after hearing six weeks of testimony in the trial, according to the Los Angeles Superior Court.

Murray, 58, who was hired to care for Jackson as he prepared for a series of planned comeback concerts in 2009, has pleaded not guilty to involuntary manslaughter, or gross negligence, in his care of the singer.

Murray, who did not testify at the trial, could face up to four years in prison if convicted.

Jackson was found lifeless at his Los Angeles mansion on June 25, 2009, at age 50. He was later ruled to have died from an overdose of sedatives and propofol, which is normally used in surgery.

Murray admitted giving Jackson a dose of propofol to help him sleep but his lawyers argued at trial that the "Thriller" singer caused his own death by taking an extra, fatal dose of the drug, along with a handful of sedatives, without Murray's knowledge.

Prosecutors say Murray is guilty of gross negligence for administering the powerful drug in a home setting, failing to monitor Jackson, delaying calling emergency services and omitting to tell medical personnel he gave the singer propofol.