The Brave One (2007)

New York radio host Erica Bain has a life that she loves and a fiance she adores. All of it is taken from her when a brutal attack leaves Erica badly wounded and her fiance dead. Unable to move past the tragedy, Erica begins prowling the city streets at night to track down the men she holds responsible. Her dark pursuit of justice catches the public's attention, and the city is riveted by her anonymous exploits. But with the NYPD desperate to find the culprit and a dogged police detective hot on her trail, she must decide whether her quest for revenge is truly the right path.

Official website: http://thebraveone.warnerbros.com/