Her story began almost 30 years ago, after the brutal murder of a 48-year-old Massachusetts woman. The main suspect was Kenny Waters, Betty Ann's younger brother.
"I told them I never killed nobody," Kenny Waters said. "I don't know what you are talking about."
But three years after the murder, Waters was found guilty and sentenced to life in prison.
"I had a five-day trial and I was away for the rest of my life," Waters said.
His sister never believed he did it.
Betty Ann said that Kenny was the life of the party, and admits he was a troublemaker. But in her heart she knew he was not a killer. So Betty Ann, a high-school dropout, enrolled in community college, then on to law school, and became her brother's attorney.
Betty Ann said that she never had a moment when she wanted to give up.
"How could I? If I gave up that would have been giving up on him and he wouldn't have made it," Betty Ann said.
She faced setback after setback, and after a long, frustrating search, finally a breakthrough.
"I felt like someone a mile away could hear my heart beat," Betty Ann said. "It was amazing."
With the help of attorney Barry Scheck's Innocent Project, she was able to show through DNA testing that the blood found at the murder scene was not her brother's - and after 18 years in prison, Kenny Waters was declared innocent.
"I think it's absolutely amazing that she dedicated her life to this," Kenny said.
Now the real life drama is hitting the big screen in the movie "Conviction."
Tragically, in 2001, 47-year-old Kenny died after a freak fall, just six months after his release. But his sister said that he enjoyed every minute of his freedom.
"I just wish he was here to see this movie. I wish he was here to live his life. I feel that he's here," Betty Ann said.
Betty Ann Waters doesn't practice law any more, but still fights for others wronged by the criminal justice system - a sister who continues to live by her convictions.