When a sophomore student shot and killed a fellow Freeman High School classmate last Wednesday, he walked unimpeded into his high school building. Just like every other student that morning.

Students and staff likely had no reason to question, much less fear his presence. Yet, less than 15 minutes after arriving Caleb Sharpe killed one student and injured three others.

The events at Freeman High School last week represent the fundamental challenge of school security: balancing the public nature of schools with safety and security.

Many districts – like Spokane Public Schools and Central Valley School District – have spent millions of dollars on security projects.

There are 1,618 cameras in Spokane schools. Secure entrances in all but two schools. Panic-style lock down buttons in every public office. Doors that automatically lock after school starts. Vestibules that could hold would-be intruders at bay.

Since 2003, Spokane Public Schools has earmarked $14.5 million in bond money toward school security. Nationwide the market for educational security systems grew to $4.9 billion in 2017 from $2.7 billion in 2012, according to research company IHS Technology.

Yet, in the vast majority of school shooting cases the violence is perpetrated by a student, staff member or parent. In other words, someone who is supposed to be there, said Mark Sterk, Spokane Public Schools director of security.

“For us, and I’ve said it over and over again, and I’m going to continue to preach it, our main defense against an active shooter is for resource officers in schools and staff to have built relationships with kids to the extent that they feel a level of trust,” Sterk said.

Between 1974 and 2013 three-fourths of school violence was committed by students. Nonstudent intruders accounted for just over 10 percent, according to a Rural School and Community Trust report.

Sterk doesn’t think the physical campus security is unnecessary. But, he’s quick to emphasize the importance of proper training, procedures and policies in conjunction with security infrastructure. He said the district’s physical security has already kept outside intruders away.

“It’s a valuable tool,” Sterk said of security infrastructure. “It’s worth every dollar we’ve spent. It’s a deterrent. It’s a hardening of the target.”

School shooting and security experts also emphasize the importance of proper staff training and student engagement. But, some believe the focus on infrastructure has gone too far.

“There has been a very skewed focus over the last four plus years on physical security,” said Kenneth Trump, the president of the Cleveland-based National School Safety and Security Services. “Security hardware and equipment. Fortifying your front entryway.”

Often that comes at the expense of staff training, Trump said.

“The No. 1 way we find out about weapons and plots … is through kids who come forward,” Trump said. “It’s not through a camera or a piece of hardware on the front door.”

It makes sense that districts would invest in physical changes, he said. It’s an easy pitch to parents and taxpayers worried about the possibility of a Sandy Hook-type shooting. It shows tangible progress and can make people feel safer. But often it’s a “false sense of security,” he said.

Trump, who serves as an expert witness in school violence cases, said at the core of most cases he’s been involved with there is one basic allegation. That school staff somehow failed.

“The bottom line is the allegations and the issues being looked at aren’t that the camera didn’t work or that the front door hardware lost a screw and failed,” he said. “It’s that there are allegations of people (failing).”

Part of that push for increased school campus security has come from companies with a vested interest in selling security products, Trump said.

He points to the Secure Schools Alliance, a nonprofit that is lobbying state and federal officials to set more money aside for security and in some cases change building codes to mandate certain school designs. The Secure Schools Alliance is also advocating for the Department of Homeland Security to partially take over the security of U.S. schools.

The nonprofit’s partnering organizations include a number of companies that build or design school security features including Allegion, a multinational security company, that, among other things, builds and sells door and access controls.

Robert Boyd, the executive director of the Secure Schools Alliance, also believes that training is critical and shouldn’t come at the expense of infrastructure. But, he said he thinks the first step in building a secure school is the building itself.

“One of the first things you need to do is protect the perimeter,” he said.

He calls schools “soft targets” and worries about coordinated terror attacks from groups like ISIS. Recently he gave a talk to lawmakers in Washington, D.C., and stressed the importance of placing barricades in front of schools to keep attacking vehicles at bay.

A prime example of where infrastructure failed was at the 2012 Sandy Hook shooting, he said. The shooter attempted to enter through the main door, found it locked and then shot the glass out. Boyd believes schools should install bulletproof glass.

“Having the training alone didn’t do you any good without the infrastructure,” he said of Sandy Hook. “It’s both. It’s both.”

Boyd’s organization advocates that school security costs be divided among the federal government, state governments and local school districts. But, ultimately he believes the Department of Homeland Security should be responsible for the security of schools. Teachers and administrators aren’t trained to handle security issues, he said.

“I don’t think school districts should be forced between books and locks,” he said.

The Secure Schools Alliance has not yet lobbied Washington state lawmakers, Boyd said. However, U.S. Rep. Rick Larsen, D-Wash., helped found the Congressional School Safety Caucus, which works closely with the Secure Schools Alliance.

An added complication in the school safety discussion is that most school shooters generally aren’t “trying to get away with it,” said Peter Langman, a psychologist who has studied and written extensively about school shootings.

“For most criminal acts, the criminals are trying to commit them and not get caught,” Langman wrote in an email. “This does not apply to school shooters (generally speaking). A metal detector might stop gang members from trying to sneak guns or knives into school because they don’t want to be caught. A metal detector may not stop a rampage school shooter.”

Additionally, most school shooters are “members of the school community,” Langman writes. People who, like Sharpe, are supposed to be there.

“All of this doesn’t mean that physical security measures have no place, but it highlights the necessity of training people to recognize the warning signs of potential violence and to have threat assessment systems in place in the schools,” Langman wrote in an email. “It is so much easier to intervene before the person shows up at school with a gun. Once you have a student show up who is armed and determined to kill, it may be impossible to prevent people from being killed.”

In Spokane, administrators and staff remain focused on the combination of school infrastructure and staff training. But, with that comes the understanding that the most visible security likely isn’t what’s going to stop a school shooting.

“If a student brings in a gym bag, are we going to look at them? ‘No,’ ” said Spokane Public Schools spokesman Kevin Morrison. “It’s a vulnerable space to a certain degree. All you want to do is harden it as much as you can. Let the bad guys know if they do come in they will be seen and make it somewhat difficult for them.”