Betty Anne Waters, a high school drop out, became a lawyer and freed her brother who was wrongfully accused of murder and imprisoned for 18 years

checks out. There is a movie called conviction about it.

Also he died 6 months after being released:

But just six months after his release in 2001, Kenny was having dinner with his mother and his brother when he decided to nip home to see if his nephews and nieces wanted them to bring some food home. He took a short cut over a fence, tripped, and fell 15 feet on to concrete. Thirteen days later, with Waters by his side in hospital, he died.

https://www.theguardian.com/film/2010/dec/11/betty-anne-waters-interview