Sal Bertolinni started out as a soldier for the Genovese crime family, working alongside his brother (Lieutenant Stripes, first name unrevealed). Then at some point, both brothers found religion and decided to repent for their crimes. Inspired by Kick-Ass, they formed the Justice Forever team and set out to clean up the city as superheroes.
Tragically, Sal ended up becoming the first victim of Red Mist and his new gang of super-villains. After killing his dog and trashing his hideout, they left his defiled body to be discovered by the police. His murder almost swayed Hit-Girl to come out of retirement. It's actually implied by Kick-Ass that he may have been in poor health before Red Mist attacked him.
As a born-again Christian, Sal didn't swear casually and despite his aggressive nature towards criminals, he was shown to be a very generous and inspirational person. During the one mission Kick-Ass accompanied him on, he displayed impressive combat skill when he took out a doorman with one strike to the throat. He and the Lieutenant used baseball bats to beat gangsters into submission and even carried unloaded firearms as a means of intimidation. It hasn't been revealed whether or not the brothers actually served in the military at some point or if the costumes/codenames are merely a theme for their superhero identities.
Colonel Stars is going to be played by Jim Carrey in the summer of 2013 release of Kick Ass 2: Balls to the Wall movie. (The name of Colonel Stars, has been changed to Colonel Stars and Stripes.)