Factbox: Tough choices for LA jurors in cop's murder trial

(Reuters) - The judge overseeing the California trial of a white police officer charged with murder in the shooting death of an unarmed black man has ruled out first-degree murder, finding there was no evidence of premeditation.

Jurors instead were given four verdicts to choose from in deciding the fate of Johannes Mehserle, standing trial for the January 1, 2009, slaying of Oscar Grant at a Bay Area Rapid Transit (BART) station in Oakland, California.

The decision hinges in part on whether jurors believed Mehserle's testimony that he mistakenly drew his pistol rather than his electric Taser weapon when he shot Grant, and that he acted out of fear that Grant was reaching for a gun.

Prosecutors said Mehserle "lost all control" and deliberately shot Grant because he was resisting arrest. Video footage taken by onlookers appeared to show Grant lying face down on the train platform when he was shot in the back.

* Jurors can find the defendant guilty of second-degree murder if they believe he either intended to kill or inflict grave bodily harm, or acted with a conscious disregard for life. In this case, the prosecution would have to prove beyond a reasonable doubt that Mehserle drew and fired his handgun on purpose. This conviction carries a sentence of 15 years to life in prison.

* Jurors can choose a verdict of voluntary manslaughter if they believe the defendant was either provoked to kill in the heat of passion or acted out of an honest but unreasonable fear for his own safety -- the so-called "imperfect self-defense" argument. Again, the prosecution would have to prove, among other things, that Mehserle drew his gun deliberately. This offense generally is punishable by three to 11 years in prison.

* Jurors can choose a verdict of involuntary manslaughter if they find the defendant lacked the intent to kill -- believing Mehserle's story that he drew his gun rather than his Taser by mistake -- but that his actions were so grossly negligent that he should be held criminally responsible. This offense generally is punishable by two to four years in prison.

* Jurors can acquit the defendant, returning a not-guilty verdict, if they feel the prosecution failed to prove a criminal act beyond a reasonable doubt.

(Reporting by Steve Gorman, editing by Dan Whitcomb)