TribLIVE's Daily and Weekly email newsletters deliver the news you want and information you need, right to your inbox. The Allegheny County District Attorney says the owners of Ross Park Mall could do more to help prevent incidents, such as a fight Saturday that led to gunfire, if security cameras were installed. “The best deterrent to criminal activity is knowing that you’ll be seen and subsequently knowing that you’ll be caught,” District Attorney Stephen Zappala told the Trib in an email Tuesday. “I have asked (mall owners) Simon Properties to do what I believe is the right thing by installing cameras and they have told me no.”