"Don't convict the defendant because of sympathy or favor," Stein said. "Convict him based on the evidence in this case."
Defense attorney Michael Rains pleaded for acquittal, citing testimony that his client had inadequate weapons training and witnesses who said Mehserle appeared to be in shock after shooting 22-year-old Oscar Grant during a fight that had drawn officers to the platform.
The incident was videotaped by several bystanders.
"On Jan. 1, 2009, Johannes Mehserle fired a single gunshot and it brought him to this place before you, and you are his shot at justice," Rains told jurors.
He also alleged Mehserle was being "smeared" to cover up for a colleague's questionable behavior.
Mehserle put his arm around Rains after the attorney concluded four hours of arguments over two days.
Mehserle, 28, testified that he mistakenly pulled his handgun instead of his Taser stun gun before Grant was shot. He pleaded not guilty to murdering Grant and resigned from the Bay Area Rapid Transit agency after the shooting.
His trial was moved from Alameda County to Los Angeles because of excessive media coverage and racial tensions that boiled over into violence in Oakland.
Mehserle is white and Grant was black. Another officer was heard on video uttering a slur before the shooting, but no evidence was presented during the trial that Mehserle's actions were influenced by prejudice.
Jurors must decide if Mehserle should be acquitted or found guilty of second-degree murder or a lesser offenses of voluntary or involuntary manslaughter.
Police in Oakland have prepared for fallout from a verdict by erecting a command staging area near the city's port. Officers received crowd control training and were working 12-hour shifts.
Several downtown businesses boarded up their storefronts. A group of activists said they would hold a rally on the night of the verdict outside City Hall.