Some schools are requiring background checks for all visitors.

Visitors to schools in a suburban Chicago, Ill., district are now required to undergo a background check as part of added security measures in the weeks following last month's shooting at Sandy Hook Elementary School in Connecticut.
Frankfort School District 157-C has installed a $2,000 system that uses a visitor's state-issued ID or driver's license to conduct an instant criminal background check through a national database, WLS reports. Those who clear the check will receive a visitor's badge with photo -- those who don't will be alerted to school officials.
"What we're trying to do is ensure that anybody that comes into the building first has a purpose for being in the building, and then once they're in the building we'll do a check to confirm that they're safe to enter and be with children," Superintendent Thomas Hurlburt told WLS.
Previously, visitors relinquished their IDs while signing in at the front office and retrieved their IDs upon departure, according to The SouthtownStar. The school also locks its external doors during the school day and requires visitors to be buzzed in to the building.
Illinois' Lincoln-Way High School District 210 has also added a background check procedure for visitors, in addition to a security management system that features 911 panic buttons.
Lawmakers across the country are introducing legislation ranging from stricter gun laws to adding armed guards and even arming teachers to protect schools.
As part of a series of far-reaching gun control proposals, President Barack Obama recommended Wednesday a federal $150 million "Comprehensive School Safety Program" that would help school districts hire school guards, counselors and other staff.
http://www.huffingtonpost.com/2013/01/25/schools-background-check-_n_2552175.html
http://www.mlive.com/news/flint/index.ssf/2008/09/two_flintarea_charter_schools.html
Visitors at Haverhill school to get background check.
MA - You may expect to undergo a background check when applying for a job or an apartment, but soon, a local high school will be running checks on every non-student who pays a visit.
It's part of a new plan for school security. In Haverhill, they're expanding the use of background checks in the district. It's one of many changes to keep students safe as they return to class.
Haverhill High School is stepping up security this year when it comes to visitors.
“Across schools nationwide, particularly here in our urban centers, there are always problems with people coming into our schools that shouldn’t be there. We have people that are convicted felons. We have people that are on an offender list,” said Jim Scully, the Superintendent of Public Schools in Haverhill.
Any person who enters the school will have their background checked electronically by swiping their driver’s license.
“We get a warning indicator that that person isn’t welcome in the schools. So what it does, it provides a safer atmosphere,” said Supt. Scully.
Another school in Haverhill, the Whittier Regional Vocational Technical High School, has been using this technology called LobbyGuard for the past two years.
“We have probably, over the last couple of years, had five or six people identified as not having access to the building,” said Bill DeRosa, the superintendent at Whittier Tech.
DeRosa explained the process to 7NEWS.
First, the visitor’s license gets scanned. Then, the person’s name and birth date are verified.
http://www1.whdh.com/news/articles/local/north/12002160246391/visitors-at-haverhill-school-to-get-background-check/