>> zac stringer: no, ma'am. >> stahl: but zac was convicted and sent off to prison for ten years. ally testified against him at trial? >> roger stringer: i did. i did. because i'd never heard of a gun goin' off without a trigger bein' pulled. it made no sense. >> stahl: what roger didn't know was that by then remington had gotten some 200 complaints claiming just that, about rifles like zac's, with a trigger mechanism called the x-mark pro. six months after justin was killed, another tragedy with the same trigger, this time in chadbourn, north carolina. 16-year-old jasmine thar and her cousin jahmesha were about to go christmas shopping. >> robert chaffin: they were standing out in the front yard, with the grandmother sitting on the porch. >> stahl: robert chaffin, an attorney for jasmine's family, made this animation: a neighbor across the street in his bedroom picked up a loaded model 700. the safety was off. >> chaffin: and it fired through a closed window. and in what could be the most random act you ever heard of, the bullet traveled across the street and went through jahmesha