Michael Carroll 
For I Have Sinned [EPUB ebook] 

Name’s Rico Dredd. I was a Judge. I tried to save my city, and they called me a criminal.Twenty years hard labour in a penal colony a billion kilometres from Earth. They gave me mechanical lungs just so I can breathe, laced my skin with polymers so I can walk in sub-zero temperatures. Stripped away everything that made me human.I was a hero and they turned me into a gruddamned monster.But maybe that was fate, because in the year 2089 disaster hit the prison, and it was down to me to save everyone.Sometimes the monster becomes the hero.