(NBC News) — On Friday’s “Dateline,” for decades, a mother searches for answers in the unsolved murder of her 14-year-old daughter Gloria until new DNA technology changes everything.

Here is a preview of Andrea Canning’s report:

After they identified Gloria’s body, police went to Yvonne’s house to deliver the awful news.

YVONNE POINTER: I remember them saying, “We found a body.”

Before they could say another word, Yvonne collapsed to the floor.

YVONNE POINTER: I was having an out-of-body experience. It’s almost like you go to a place– of comfort, of denial.

Friday on “Dateline,” for decades, a mother searches for answers in the unsolved murder of her 14-year-old daughter Gloria until new DNA technology changes everything.
Friday on “Dateline,” for decades, a mother searches for answers in the unsolved murder of her 14-year-old daughter Gloria until new DNA technology changes everything.

Yvonne’s denial was easy to understand. Just hours earlier, Gloria had bounded off to school, upbeat and full of life. Typical Gloria.

ANDREA CANNING: What kind of daughter was she?

YVONNE POINTER: Gloria was the type of daughter that every mother wish she could’ve had. Very obedient. Just a caring, loving person. A child that the school loved, and the teachers loved, and everybody. And I probably make it sound like she was so perfect, but she was.

ANDREA CANNING: What happens that– in those first days? What are you doing? What can you do?

YVONNE POINTER: The first days after the homicide, you’re just trying to adjust to the emptiness. But now you have a funeral to plan. How do you plan a funeral for your child?

At the funeral home, Yvonne was warned not to look inside the casket. But she insisted on having a private moment with her daughter.

YVONNE POINTER: I pulled the cover back and I just looked at her from head to toe. And I said, Gloria, don’t worry. I’ll find out who did this.

ANDREA CANNING: You made her a promise that day?

YVONNE POINTER: I made a promise to her. And grief took a backseat at that moment. ‘Cause we needed to find the killer.

Watch “Dateline: A Promise to Gloria,” Friday at 10 p.m. on NBC4.