Claudia Rivero reports

For nearly a week, investigators searched for the identity of a murdered girl known only as Jane Doe.

They now know the girl is 13-year-old Brenda Nguyen.

With the help of a friend, Thuy Nguyen describes the moment she learned her 13-year-old daughter was the girl found dead in the alley, who for eight days had only been known as Jane Doe.

Nguyen said she never thought it was her daughter because it's not the same picture.

Detectives were baffled as to why nobody had come forward to identify the teen.

They would later learn that her mother had filed a missing person's report on Feb. 11 after Brenda and her 14-year-old friend, Arlene Cota, ran away.

"We have 1,200 missing juvenile open reports," said Sgt. Joel Tranter with the Phoenix Police Department. "(The) detective was going through reports one by one and at the same time we were getting calls from families saying we think that's my daughter."

Nguyen, who is nine months pregnant, said she did see a composite sketch on television, but wasn't convinced that was her daughter until a friend saw Brenda's autopsy photo on the Internet.

She said when she saw the picture she felt like she was dying, too.

And while one mother deals with the loss of her child, Kimberly Cota said she is breathing a sigh of relief as her daughter, Arlene, called to say she wanted to go home.

"I was waiting by the door so I could hug her," she said.

Arlene said she and Brenda had been staying with friends then at a local park. The last time she saw her was two weeks ago.

"She said you should go home, too. I said all right," Arlene said. "I just hugged her, told her to keep in touch and then she was like all right and we went our separate ways."

Arlene said she had no idea Brenda was dead.

"I had heard a couple of days ago that she got raped and they dumped her in a Dumpster," Arlene said. "I didn't think it was true."

For now, Brenda's mother is left with more questions than answers and memories of her little girl who loved basketball, school and dreamed of being a model.