. >> reporter: michael slager said he pulled scott over for a broken tail light of 2015 and was preparing to write him a warning, but scott bolted from his car. >> in my mind, at that time, people don't run from a broken tail light. >> reporter: prosecutors say he fled because he was behind on child support payments and was in fear of being arrested. >> i was in total fear that mr. stop. >> reporter: the cell phone video, he says, picks up the encounter seconds later as scott breaks away from the struggle. the prosecutor pressed slager on why he moved the taser closer to scott's body. >> you don't leave a weapon in the middle of a field like that. >> reporter: slager said in hindsight he would not have chased him on foot and instead called for backup. >> his entire testimony was what he would have done different and things he's remembering now >> reporter: the jury, made up of 11 white people and one black man, is expected to begin deliberations later this week. gabe gutierrez, nbc news. >>> still ahead here tonight, detecting breast cancer, the alarming number of women being diagnosed wi