Police are searching for evidence and will have extra patrols at arrival and dismissal at the Northwest Side school starting Thursday. CBS 2's Charlie De Mar reports. ***************************************************** ABOUT CBS 2 NEWS CHICAGO: Honored as the Edward R. Murrow winner for overall excellence, CBS 2 News Chicago brings you breaking news, weather, compelling exclusive content and award-winning investigative reports from the CBS 2 Investigators. Subscribe to CBS 2 News Chicago on YouTube : http://www.youtube.com/user/cbschicago CBS 2 NEWS 24/7 LIVESTREAM: https://www.cbsnews.com/chicago/live/ CBS 2 NEWS WEBSITE: https://www.cbsnews.com/chicago/ FACEBOOK: https://www.facebook.com/cbschicago TWITTER: https://twitter.com/CBSchicago GET THE CBS 2 NEWS APP: https://apps.cbslocal.com/chicago/