From the film website:
Writ Writer documents the remarkable transformation of Fred Arispe Cruz, from a barrio delinquent on drugs to the hero of the prison reform movement in Texas.
Coming of age at the dawn of the Civil Rights Movement, Cruz landed in prison for robbery in 1961. Horrified by the rampant brutality of prison life, he studied law religiously and wrote a string of lawsuits against the prison system.
His pen and writs of habeas corpus—along with help from a "lady lawyer" sent to assist the poor—shook the prison system to its core, and launched the historic prisoners' rights movement in Texas.