Less than one-third of the Chicago area's 2,124 elementary, middle, and high schools do not report any incidents to a School Incident Reporting System.

According to NBC5, that means there is no clear way for the public to find out what is happening inside nearly 1,500 schools in Chicago and across the suburbs. What's more, there are no penalties for any school that chooses not to report to SIRS.

NBC 5 Investigates obtained a database of all incidents reported to SIRS for the past two-and-a-half years, covering Chicago plus every suburban town in Cook, DuPage, Kane, Lake, McHenry, and Will counties.

"In all, we found a total of 646 city and suburban schools that do choose to disclose their incidents directly to SIRS. And for just those 600-plus schools, we found thousands of reports of drugs; assaults on teachers, students, and other school personnel; and weapons at schools throughout the city and suburbs," it said.

Weapons alone accounted for a total of 1,428 incidents examined by NBC 5 - with 314 of those weapons reports were from suburban schools.

Half of all the weapon incidents involved knives or other cutting instruments such as switchblades and razors. Other incidents involved hammers, ligatures, and broken glass. And NBC5 Investigates discovered a total of 92 incidents involving firearms or explosives - including 55 incidents in Chicago schools, and the other 37 in schools throughout the suburbs.

But the incidents that are not included in the state database - incidents at the nearly-seventy-percent of Chicago-area schools that don't use SIRS -- may be a bigger cause for concern, NBC 5 said.

According to NBC 5, the law itself may be part of the problem. "Illinois law clearly states that schools must report all incidents of weapons, assaults and drugs to both local police and Illinois State Police. The law also mandates that this information should be available to the public. The School Incident Reporting System is supposed to help serve both of those purposes - but only if a school chooses to use it," it said.