Huntsville City Schools is the first known school system in Alabama to use a new type of security to detect weapons.

The district has been adding new sensors to several schools and athletic events since December under a $2.86 million contract with Evolv Technology.

The effort comes amid recent safety complaints, including three incidents where students reportedly had a possession of a gun on campus last school year. According to student discipline reports, there were 80 incidents where students were in possession of another, unspecified weapon. And in three separate incidents in January, students at Mae Jemison High School and Lee High School were found with guns.

How does Evolv’s security system work?

The system looks like a metal detector, but students don’t have to line up and pass through single-file. It looks similar to security monitors in stores that catch shoplifters.

Evolv Technology, the detection system, says it works 10 times faster than metal detectors, allowing people to move through detection without forming a line or stopping to remove backpacks or objects out of pockets. According to the company, the system combines sensor technology, artificial intelligence, ecosystem integrations and venue analytics to provide a more accurate threat detection.

The district said Evolv devices do not collect any personally identifiable information.

“Much like how we are used to security protocols at airports, concerts, and sporting events, we are taking the same approach in our schools,” HCS Superintendent Christie Finley said in a news release. “We ask families for their support in this effort as the most effective weapon detection occurs before students ever set foot on campus.”

HCS is the first district in the state to use the technology, though it’s used by 200 schools across the country as well as sports venues and airports.

One school district in Utica, New York removed the technology from their schools in October after a student passed through the detection system with a knife and later used it in a fight with a classmate.

The New York district also says the system showed flaws in multiple instances, including “an off-duty member of law enforcement who accidentally brought a service revolver to a school open house and did not trigger the alarm, and a student’s metal lunch box, which triggered an alarm at an elementary school.”

Evolv responded to the Utica Dispatch-Observer’s inquiries into the instances, saying “there is no perfect solution that will stop 100% of threats, which is why security must include a layered approach that involves people, process, with the integration of various technologies to best mitigate risk.”

According to reporting by the BBC in November, “independent security experts have expressed doubts about some of Evolv’s claims” about their system’s capabilities.

IPVM, a security and surveillance research group, found that Evolv’s systems failed to detect 42% of knives, prompting members of the British government to ask for more evaluations of the system before its rolled out into more venues in the United Kingdom.

The BBC’s article also noted “for security reasons, BBC News is reporting no further details about the documents’ suggestion [Evolv] may also fail to detect certain types of bombs and their components.”

When asked whether HCS was aware of these shortcomings in Evolv’s system, the district told AL.com that the school district is still working to determine the best ways to deploy the system.

HCS sent five vendors an invitation on Nov. 2 to bid to provide the district with a concealed weapons detection system. Only Mobile Communications America of Huntsville, a partner company of Evolv, responded.

The district’s procurement director sent a memo to Finley on Nov. 15 advising her to accept the bid for $2.86 million. The contract was later finalized following a December school board meeting.

According to Craig Williams, communications director for HCS, “an important factor in selecting these systems is the efficient screening process versus traditional metal detectors.”

The school district has been deploying the systems, which are monitored by the HCS security team, at various schools and athletic events since December.

The Evolv systems will be rotated among locations across the district. Administrators are asking parents to check children’s backpacks before they leave for school.