A remarkable story of an actress who located her father's killer after 26 years. It's a determined search for justice. And abc's dan harris has the story. Reporter: She's beautiful. She can act. She... See More
A remarkable story of an actress who located her father's killer after 26 years. It's a determined search for justice. And abc's dan harris has the story. Reporter: She's beautiful. She can act. She can sing. ♪ I will survive ♪ Reporter: But her lasting legacy may be her ability to fight crime. I just forget it. Reporter: In 1986 when joselyn martinez was just 9, her father, jose, was shot and killed outside of his successful dominican restaurant in new york city. They shot him outside. Reporter: The police identified a suspect. 16-year-old justo santos. He moved to the dominican republic and the case went cold. But joslyn martinez never forgot. She spent her free time on the internet trying to find santos. She found sites that allow background searches on people. And there it was, somebody with the same name and birthday as the alleged killer, living in florida. That's a pretty big revelation. It's like not real. This isn't be. Reporter: Joselyn gave the information to police. And on thursday, santos was arrested. It paid off. Reporter: Shouldn't the police have been doing the work that you've been doing? There's a lot of crime going on. Reporter: The department mistakenly closed the case when they heard santos was in prison in the dominican republic. In fact, he was arrested. However, he was only in jail for a little over a year. Reporter: Upon his arrest in florida, police say santos confessed. Closing a painful chapter for joselyn martinez. All the time alone, thinking. And talking about it. For that person, I'm happy for. Reporter: For "good morning america," dan harris, abc news, new york.
This transcript has been automatically generated and may not be 100% accurate.