RATHDRUM, Idaho (AP) - Two northern Idaho school districts have installed new security systems that will check visitors' photos and identification against registries of convicted sex offenders in Idaho and 41 other states.

Beginning this fall, visitors to schools in the Lakeland and Post Falls districts will be required to present a state driver's license or a state-issued photo identification card to school employees, who will then use an optical scanner to check names, photographs and birth dates against a database of registered sex offenders in 42 states.

Eight states - Oregon, Nevada, Hawaii, North Dakota, Missouri, Oklahoma, Pennsylvania and Maryland - do not compile their state sex offender registries with enough unique identifying information to be searched by the software system marketed by Texas-based Raptor Technologies, according to company officials.

If the system finds a match, the registered offender's picture appears on a computer screen along with a flashing red message. Cell-phone text messages notifying school administrators and local law enforcement officers of a sex offender on premises can also automatically be sent by the system.

"School districts are trying to provide safe learning environments for their children," Ron Schmidt, assistant superintendent of Lakeland School District in Rathdrum, northwest of Coeur d'Alene, told the Spokesman-Review newspaper. "This is one more way to ensure that."

"We're feeling pretty obligated to put the accelerator on this one," said Post Falls District Superintendent Jerry Keane, who began looking at the visitor background check software this spring after a parent discovered the husband of one of the teachers in the school district was a registered offender and had visited the school.

Post Falls bought three of the systems to test at schools and will require visitors to be cleared at one of the three schools before entering any school in the district.

Lakeland district officials learned about the system from Keane and purchased one of the scanning units to try out last month.

"Within a day they called and ordered six more," Carol Measom, the company's marketing director, said Thursday.

More than 900 schools in the U.S. have installed the systems, which have an initial equipment cost of $1,824 per school and an annual subscription fee of $432. Coeur d'Alene school system officials are considering buying the software. None of the systems has been sold yet in Washington state, Measom said.

She said a school in Marble Falls, Texas, discovered two weeks after purchasing the software that the man who regularly stocked the school's vending machines was a registered sex offender. Other schools using the sex offender background check system have reported finding workers hired for construction and maintenance contracts were registered sex offenders.

"We get sex offender alerts almost daily when school is in," Measom said. "Most of them are parents. That's the thing that has surprised us most."

Keane said with the advent of the new visitor background checks, the Post Falls district is developing policies on what to do if a registered sex offender is identified by the system.

"We have parents that probably are sex offenders," Keane said. "What do you do about that?"

Schmidt said Lakeland schools will handle parent sex-offenders on a case-by-case basis and will limit their contact with students. Other visitors who are identified by the system, however, will be prohibited from entering school grounds.

"We'll have them leave the campus," he said.