Who is Celeste Viruet from The Savage City: Race, Murder, and a Generation on the Edge and what is their importance?

Celeste Viruet is Elba Borrero's sister-in-law. Over the course of the story, she proves to be George Whitmore's last ray of hope. George had been incarcerated close to ten years when it was finally decided that the one loose end - Celeste Viruet, who witnesses the Elba Borrero attack through her window had only been interviewed once and never called as a witness. George's attorneys found Celeste in Puerto Rico, and her information was enough to force a reexamination of George's case and ultimately freed him from incarceration.