>> reporter: as far as detective pate could determine, it all came to a head on christmas eve. jermeir walked into his greensboro church with denita on his arm, and a diamond ring on her finger. he had proposed, and denita was over the moon. >> she walked into church proud as a peacock, feathers just completely on display, showing that hand to anyone who would look. and shannon was in the back of the church at the time and saw that. >> we heard that was the first time shannon realized that they were engaged. >> reporter: shannon's family says the d.a. and the detective heard wrong. >> the day that -- that you're referring to, the church, shannon wasn't there. we were there. >> reporter: less than two weeks later, denita smith would still be wearing that engagement ring, as she lay dead at the bottom of her apartment steps. now, just as assistant district