Transcript for Mom discovers daughter brutally attacked by man with shovel: Part 1
Reporter: It's been said that our lives are built one memory at a time. No experience ever really gone as long as we remember. But at the center of this story is a memory that was lost. Here in Albuquerque, New Mexico, in 2008, life for 17-year-old Brittani Marcell was as carefree as the sky over this city's annual hot air balloon fiesta. She lived in this house with her single mother Diane, one of seven siblings. Tell me what life was like, 2008, in your house in Albuquerque. I had at that time five kids living with me. Two were on their own. And it was joyful. A beautiful family and a lovely life and I couldn't have asked for anything better. Reporter: Brittani fell right in the middle of her boisterous family. Number five of seven. Kathlein Guinn and Alicia Marcell are two of her older sisters. She had a great personality. She would talk to anyone, very outgoing. Everyone knew her for her positivity. I know it's a cliche to say but she was going places. She had dreams and goals and she was taking care of them. Reporter: One of those dreams, to be a television reporter. But for now the high school senior held down a more modest job at the local mall. She worked at a sunglass icon. Talking people into buying them. Reporter: The mall was just down the road from where the Marcell family lived on the west side of Albuquerque, a cozy swath of suburbs just off the Rio grande. Our neighborhood was perfect. It was nice. Nothing happened like that. Reporter: Which made what did happen here on September 11th, 2008, so unfathomable. It was a Thursday and Brittani would be out of school early. She said, do you want to meet for lunch. I said, sure, where do you want to go? And she said, let's just meet at home. Okay, fine. Reporter: And you called her as you were driving home? I did. Reporter: And what did you say to each other? Reporr: Minutes later Diane pulls into her driveway and walks into a terrifying scene. I unlocked the door and I see this guy with a shovel and she's over here to the left at the bottom of the stairway, bleeding and I thought really she was dead. Reporter: Diane can't believe her eyes. Her daughter lying on the floor beaten and bloodied. Her purse, shoes, and DVDs are scattered just inside the door, dropped as she was hit in the head by a man wielding a shovel. But the assailant was right there, standing over her. And he looked at me and he just -- Reporter: You made eye contact. Right. He turned around and he, he had the shovel in his hand still. This guy takes off for the kitchen and he looked at me as he reached for the biggest butcher knife out of the knife block on the counter. And he said, you're next. Reporter: Diane runs frantically from the house screaming. A neighbor on the street comes to her aid as she dials 911. What is your name? Diane Marcell. I said, my daughter's been beaten and the guy's probably still in there. I'm afraid he might be in there! Oh, my gosh. This is a life or death situation, can they hurry? Reporter: Even before police arrive and unaware the attacker has escaped, Diane is running back into the house with that neighbor, desperate to save Brittani's life. Can you come with me, please. I'm so afraid. Reporter: The entire course of your life changed in seven minutes. It did. Is your daughter breathing right now? She' breathing, but moaning, she's going to lose consciousness, please, there's blood everywhere. Her face was already swelling. Her head was swollen already from the beating. Her arms were bruised. And she was moaning. We had a homicide call out, there was an individual on the west side that was attacked inside of their house. Reporter: Jason morales was a detective on the case. He's since retired from the Albuquerque police department. Myself and the other homicide detectives responded to the scene. Reporter: Brittani is whisked away in an ambulance. Detectives want to speak to Diane immediately. What did they ask you specifically? They asked what he looked like and I told them. He's either a dark caucasian or a light hispanic I said he was a light hispanic, I said he was probably 5'7" or you know 5'11", in that range. Probably in his 20s. Reporter: Investigators assess the scene, trying to determine what actually happened. The entire house had not been touched. Reporter: Detective morales collects the weapons left behind by the attacker. We had the shovel that he was holding when Diane walked in, there was also duct tape at the scene, and then the fact that he had armed himself with a knife. Reporter: And there was something else that attacker left behind. The suspect actually went through a large living room window instead of exiting out of the sliding glass door. He cut himself, leaving his blood. One perfectly round drop of blood. A calling card inadvertently left behind by whoever did this. They had his DNA. Now all police needed to do was find the guy. As Diane rushes to the hospital, the rest of the family gets word. When we saw her we realized how very, very bad it was. There was severe brain trauma. They said that she did try to fight him off because she had severe bruising on each arm at the upper part. Her left wrist was broken, her jaw was broken. When we finally went in, we just dropped. "This is Brittani, no." Her head was like a huge balloon, face swollen, bruised, battered. I had that terrible feeling because when the detective came he said he was a homicide detective and I was like, "No one thinks she going to make it." Reporter: That detective needs Diane's help again. Now we need to go down to the station, make a sketch. The quicker we get it out, the quicker we can publicize it. This is the man police want to talk to in connection with a vicious beating. Reporter: As police start fielding tips, Brittani's family can only pray she will somehow
This transcript has been automatically generated and may not be 100% accurate.