Transcript for 'The View's' Sunny Hostin on what motivated new cold case show, 'Truth About Murder'
I mean, did you advise your boyfriend that it is a federal crime? Reporter: You might think you know sunny Hostin. It is a crime. That's not accurate. My law degree says it is. But nevertheless -- Reporter: Former federal prosecutor -- Intimidating that witness and he's encouraging people to break the law. Reporter: Legal guru at ABC news. Now you have not one but you have two people saying these are baseless allegations. Reporter: Turned fireball co-host of "The view." If I can finish what I was going to say. Okay. Then maybe you would hear me. My name is sunny Hostin. Nothing is more important to me than the pursuit of truth and justice. Reporter: Now sunny's taking her legal know-how and going from the studio to behind the yellow tape. For her new show "The truth about murder." This is a photograph of Kelsey's home at the time. Reporter: Where she goes after cold case files across the country. What made you want to do "The truth about murder"? My kind of story was giving a voice to the voiceless. Giving the victims a chance to explain what it feels like when you are victimized. What it feels like when your daughter's taken from you. Reporter: The investigation discovery series comes from a deeply personal place. As a child she witnessed a horrible crime. I saw my uncle stabbed in front of me as a young child. I was about 7. I know, I don't tell the story very often. I'm so sorry. How traumatic. I know. It changed our entire family. But what I remembered was the police didn't seem to take it seriously. No one was prosecuted. And the case was forgotten. The truth is that a lot of crimes aren't investigated. The truth is it takes a lot to get a conviction. The truth is it affects communities, it affects families, it affects everyone. Is that part of the reason why you became a prosecutor in the first place? Absolutely. Absolutely. The most power in the courtroom is in the prosecutor. You get to choose which cases are prosecuted. You get to run investigations. You get to make sure that justice is served. Justice wasn't served in my uncle's case. When I was a prosecutor, I made sure justice was served because I never lost a case. Reporter: Growing up half black, half Puerto rican in the south bronx, sunny's family struggled with poverty. We didn't have a lot of money. You know, my parents were teenage parents. But we had so much love. They're my role models. I am because of their sacrifice. Reporter: Her challenging childhood made her a champion for the underdog. Her show spotlighting stories of neglected victims. I also wanted to highlight people of color because we don't talk about people of color enough when they're victims. I wanted to highlight people in the lgbtq plus community because we don't do that enough. Reporter: Just after 1:00 A.M. On a dark stormy night in Georgia the 911 call comes in. I hear a baby crying. She hasn't responded. Reporter: In the series premiere the show dives tone a murder case that had gone unsolved for years. 23-year-old single mom Danielle Marshall shot and killed in her own home. As her infant daughter crawls nearby. This was premeditated. Reporter: And a clever killer with an airtight alibi. We can't break his alibi. We can't put him on the scene. This is a gruesome murder. Execution style. She was pistol whipped and shot execution style in the head. Yet what cracked the case in the end? It was a cold case for a while. It was technology. What a lot of people don't realize is even when you're not using your cell phone if your cell phone is on it is being tracked. Reporter: Danielle's killer, her abusive ex-boyfriend, Joshua Gibson. It was a lot of thought that went into this, a lot of thought about how to deceive law enforcement, how to avoid detection. This is unbelievable. If you look at the statistics, you know, we talk about stranger danger all the time with women. You know. And we teach our girls be careful, stranger danger. And to be clear, that's important as well. But most women are harmed by people they believe love them, people that they know. Yeah. And I wanted to make sure that was told. Danielle knew and loved the person that killed her. How sad is that? How did the case end up? Josh took a plea. And then very shortly after he arrived in prison he took his own life. So he could commit the crime but he couldn't do the time. Reporter: This former sex crimes prosecutor still crusading on behalf of women. For Danielle's mother Gloria, she did not want to do this story. I said hi, miss Gloria, I hate to bother you but I really think your story's important. If this story helps one person not to become a victim of domestic violence or murder, I really think we'd be honoring your daughter. And she cried and she said, okay, I'll trust you. And when she said, you know, I should have kissed her, and I walked out and it was the last time I saw her. Juju, since I did that interview, I go into my kids' rooms every single morning and I kiss them. Reporter: Now with two TV shows, a true crime podcast, and a memoir on the way, the real sunny Hostin is just getting started. People say you're my role model, like you're my inspiration. And I'm always a little uncomfortable with the whole role model thing. I always tell my kids do you because no one else can do it as well. Our thanks to juju. You can watch sunny's show on the investigation discovery channel.
This transcript has been automatically generated and may not be 100% accurate.