Johannes Mehserle was found guilty for for killing Oscar Grant, an involuntary manslaughter case which happened way back in the New Year's Day of 2009. He was the BART officer who received his final verdict on January 1, 2009 incident. According to report, he just accidentally shot the man with his own gun although he stated in court that he'd like to use his tasser but he pulled a wrong one.
There's a video after this cut taken by a resident who's one of those eyewitnesses during the incident. Johannes Mehserle pleaded not guilty but the evidence filed in court could not deny the fact. Grant Oscar died by the next day on the hospital after and receive his justice from almost one-year of trial.