For 18 months, former Bay area transit officer Johannes Mehserle maintained a public silence about what led him to shoot unarmed Oscar Grant as he lay face down on an Oakland train platform.
More answers may come on Friday when Mehserle resumes testifying at his murder trial in a Los Angeles courtroom. His testimony marks the first time he's spoken publicly about the shooting early New Year's day 2009.
Mehserle, who is white, has pleaded not guilty to the 22-year-old black man. The trial was moved from Alameda County because of intense media coverage and racial tensions.
In a surprise move Thursday, Mehserle took the stand and told jurors that training he received didn't emphasize the possibility of mistaking his stun gun with his handgun.
But that's what his lawyer claims happened when Mehserle pulled out his .40-caliber handgun and shot Grant.
On questioning by defense lawyer Michael Rains, the brawny, 6-foot-4 Mehserle said he received Taser training in December 2008 and had only pulled it out once while on duty in the month before the shooting.
He said his former employer didn't put much weight on possible "confusion issues" where officers should place the Taser holster, only that the weapon wasn't to be put under their issued handgun.
"They left it up to us to figure it out," said Mehserle, who spoke in a calm, soft voice. "For me it wasn't that big of a deal."
Prosecutors say Mehserle intended to shoot Grant, and that Mehserle used his handgun because officers were losing control of the situation. Mehserle wore his stun gun on the front left side the night of the shooting, while his handgun was mounted on his right hip.
The trial adjourned late Thursday before Mehserle could give details about the shooting.
Legal experts say while defendants in criminal trials rarely take the stand, his testimony could be compelling for jurors.
"They are going to want to get a sense of is he a good person, a thoughtful person," said Dr. Philip Anthony, a Los Angeles psychologist who is chief executive of the jury consulting firm DecisionQuest. "Most importantly, they want to hear what was running through his mind, his thought process when he fired that fatal shot."
On the stand, Mehserle did say when he arrived with his partner to the train station in response to a possible fight, that he could hear yelling and screaming from the platform above.
"I remember it being real loud," Mehserle said. "I didn't know if officers were involved in the fight or the crowd had turned on them. It didn't sound good."
He added he intercepted a few men who he said were approaching two fellow officers that had detained Grant and several friends against a concrete wall. He said the men, who turned out to be more of Grant's friends, were taunting the BART officers.
"I just instructed them to get back," Mehserle said.
He said he eventually looked at Grant and Jackie Bryson, who appeared to be upset. The other two officers, Tony Pirone and Marysol Domenici, had pulled their stun guns out and given the situation, Mehserle said he decided to do the same. Before Grant was shot, he snapped a photo of Mehserle pointing his Taser stun gun in his direction.
Mehserle said he wasn't sure what had transpired but tried to cool down Grant and Bryson.
"They were yelling '(expletive) that officer,' 'I'm going to sue,'" Mehserle recalled the two men saying of Pirone, who was described by some onlookers as the most aggressive and hostile toward Grant and his friends. The shooting, and the events leading up to it, were captured on video by several bystanders.
Grant's uncle, Cephus "Bobby" Johnson said he believes Mehserle will try using his testimony to differentiate himself from Pirone.
"Now all of the sudden he's this huggable, passive, non-aggressive person who really believes in communication instead of exerting authority," Johnson said. "I'm not buying that."
Associated Press Writer Terry Collins contributed to this report.
© 2010 The Associated Press.