Cyntoia Brown is accused of killing 43-year-old Johnny Allen at his home in August, 2004.
She claimed it was self defense two years ago when Allen picked up Brown as a homeless teen.
"He was a man of kindness, and I know he took her into his heart to try and help her," Allen's former fiance Nancy Liker said. "At his church, he always helped, and especially helped the homeless."
Allen met Brown at a Sonic, where she claimed that she was homeless.
"We know that Mr. Allen showed her around his house. The two were together Friday night, Saturday morning," Don Aaron, of the Metro Police said.
Police said she shot Allen in the head while he slept, then robbed him. Brown was later found at a nearby motel.
"During an interview with officers, she did admit shooting Mr. Allen," Aaron said.
Brown said she was scared, because she thought Allen was reaching for a gun. Her attorneys have argued that Allen had a dark side, and that she feared for her life. They also said that Allen was reaching for a gun when Brown shot him.
The prosecution claimed that was impossible because of the way his body was found.
"He was laying face down in the bed. Both his hands were underneath his face," Metro detective Scott Carter said.
The court has already decided to try Brown as an adult. She was 16 at the time of the shooting.