In St. Paul, Minnesota, a police use-of-force expert said from the witness stand Wednesday there was “absolutely no reason” for officer Jeronimo Yanez to open fire on Philando Castile during a traffic stop last year, as Yanez’s trial on manslaughter charges entered its third day of testimony. Prosecutors opened the trial by playing a police dash cam video of Castille’s killing on July 6. It shows officer Yanez opening fire on Castile seven times. A medical expert testified Castile was struck with five of the rounds, including two which pierced his heart. Castile’s death was live-streamed on Facebook by his girlfriend, Diamond Reynolds, in an extraordinary video, in which she narrated the aftermath of the shooting while she was still in the car, with officer Yanez pointing a gun at her and her 4-year-old daughter.