As students arrive at St. Paul public schools Tuesday, some will pass through new entrances that require card access once school is underway. There will be cameras, new motion detectors and an upgraded alarm system. Ten police officers and 40 contracted guards will patrol the district's schools.

Visitors to Anoka-Hennepin elementary schools will need to swipe a driver's license to gain entry. A similar scanning system at Stillwater middle schools will tap into a national sex-offender base before printing out a visitor's pass.

And while three metro-area districts brace for referendums to raise millions of dollars to bolster school security, others debate installing coatings to make glass more shatterproof, renovating school entrances and whether they should hire more police liaison officers or private security.

As the first new school year begins since 20 elementary-school children and six staff members were shot to death at Sandy Hook Elementary School in Newtown, Conn., last December, security concerns are testing school officials throughout the nation like never before. In Minnesota, officials not only wonder how to pay for improved and added security, but grapple with a new equation that adds up differently from district to district: How much security is too much?

"There's a fine line between building a fortress and maintaining a safe and caring learning center," said Susan Brott, spokeswoman for Edina public schools.

"Schools have to be inviting," said Jason Matlock, director of emergency management and safety for the Minneapolis district, which continually adds cameras, has entryways that require ID cards, and uses 16 police liaison officers and 100 staff members to patrol school halls. "If you harden a building too much, what kind of message is that sending?"

It's a question facing voters this fall in Bloomington, Chaska and Stillwater — communities with referendums focused on school safety improvements. Bloomington is asking voters to spend $2 million a year for security measures. The eastern Carver County district of Chaska, which lost three of its four resource-officer positions to budget cuts, is seeking $1.8 million to renovate entryways, add surveillance cameras and install a key-list door-swipe system to help monitor visitors. As part of its levy request, Stillwater is seeking an additional $450,000 for eight years to remodel school entrances and improve communication systems.

The (expensive) human factor

But the greatest debates concern the guards behind the entrances.

Before Sandy Hook, there were an estimated 10,000 law-enforcement officers patrolling the nation's schools, according to the National Association of School Resource Officers.

"Since Sandy Hook, it's like the lid has blown off," said Mo Canaby, the group's executive director. Canaby said his association — formerly based in Woodbury and now in Alabama — recently completed its most extensive training period and successful national conference in its 23 years.

Several Twin Cities metro-area districts have police liaison officers who patrol high school entrance areas and halls. Other districts have balked at spending the average annual cost of $70,500 per officer.

"You want the best technology available, but there's a cost associated with all this security and safety," said Kathe Nickleby, principal at Mahtomedi High School, the only high school in Washington County whose halls are not patrolled by sheriff's personnel. Mahtomedi saved $47,000 by opting instead for an unarmed, full-time security guard.

At least three states have passed laws allowing teachers to carry handguns in schools. In Clarksville, Ark., the school district has proposed arming 20 teachers, all of whom have a history with firearms, said Superintendent David Hopkins. If the proposal is approved by the state, students "ideally would not know" which teachers are armed, Hopkins said.

"In Minnesota, you guys have conceal-and-carry permits," Hopkins said. "All we're trying to do is protect our kids."

Rick Kaufman, director of community relations and emergency management coordinator for Bloomington public schools, says there is "no cookie-cutter approach" to protecting students. He had studied to become a paramedic before opting for a career in school communications. In 1996, while working in Sheboygan, Wis., he designed a mock "shooter's drill," devising a plan in case a worst-case scenario burst through the school doors.

Called to Columbine

Three years later, while working in Colorado's Jefferson County, he got the call. There was a shooting at Columbine High School. He was at the school within 10 minutes, "triaging the wounded."

"Our society has changed," Kaufman said. "Schools have had to adapt to that. There are so many schools you can walk right into. Some don't have the resources or technology to change that. And not all schools want to.

"How do we not create these facilities that kids are afraid to come to?"

For John Patrick Egelhof and Francis Brun, Sandy Hook hit too close to home. And it had nothing to do with one of the victims, 6-year-old Charlotte Bacon, whose mother, JoAnn Hagen Bacon, grew up in Orono.

Egelhof is a former FBI agent who was summoned to Red Lake High School in 2005 on the day 16-year-old Jeff Weise went on a shooting rampage. Weise, a student, killed his grandfather and grandfather's companion before going to school and killing a security guard, a teacher, and five students, and wounding five others and then committing suicide.

The unarmed guard was Derrick Brun, Francis Brun's son.

"There should be more armed officers in school," Egelhof said recently. "It's cost vs. the acceptable risk, or casualties.

"We put teachers in a position where they're expected to take care of their own students, really at the risk of their lives. That's not fair."

Paul Levy • 612-673-4419