A successful young attorney is gunned down in his own home. The shooter? His on-again, off-again girlfriend, a beautiful, young graduate student. She says it was self-defense. Police say it was something else.At the time of his death, Poston was a 29-year-old self-employed lawyer with a promising future ahead of him. Hubers, too, was "very, very, bright," according to Highland Heights, Kentucky Police Chief Bill Birkenhauer."When he walked into a room, he immediately demanded attention," says Poston's friend, Allie Wagner. "And he got it. He was a very good-looking guy and he had a very big heart."What is certain is Hubers shot Poston. She admitted she shot him the moment she dialed 9-1-1. But what led to the shooting, however, is where the story takes unexpected turns. After the incident, Hubers was taken to police headquarters. There, she told police she wanted a lawyer but then, unexpectedly, she began talking on and off for more than two-and-half-hours with a police camera rolling. Hubers also danced, sang and snapped her fingers humming, "I did it! Yes, I did it." Portions of the video will be broadcast by 48 HOURS.