Following the bombing at the Boston Marathon in 2013, Mike Ellenbogen ’86, who lives in the Boston area, began pondering what it would take to prevent a similar act of violence at a large public venue.

It wasn’t the first time that Ellenbogen — a physics major who began his career in semiconductors before moving into security — had been moved to shift his research following an act of terrorism. After the bombing of Pan Am flight 103 over Lockerbie, Scotland, Ellenbogen worked on a team that used medical X-ray technology to develop a scanner to detect explosives in suitcases. Soon after 9/11, he formed a team to find a fast and cost-effective solution to scanning baggage going into airliners. He created Reveal Imaging Technologies and came up with a device that was easy for airports to deploy. Reveal’s scanner is still used at more than 300 airports nationwide, screening millions of bags each day.

The Boston Marathon bombing posed a very different threat than the aviation attacks. “You are working with a large, nonregulated space. People want a safe environment, but not necessarily a sterile environment, which is how people refer to an airport,” Ellenbogen explains. “With aviation, you have to ensure there are zero threats going through that could be used on an aircraft.”

The difference in venues demanded a fresh approach. Ellenbogen founded a new company, Evolv Technology, and set to work to find a low-impact threat detector for use in outdoor venues like sporting events, or to quickly screen vast numbers of people at indoor events like a trade show or convention. For these locales, speed is of the essence. “With stadiums, hospitals, schools, or performing arts centers, you can’t have a line going around the block. You need a security system that doesn’t create so much hassle that people get fed up,” says Ellenbogen. “The last thing you want for a concert or the Detroit Auto Show is a long line of people fuming as delays mount.”

Ellenbogen’s answer is a scanner that can screen up to 4,000 persons per hour as they walk through it at a normal pace. “It’s completely seamless,” he says. The security scanner is no more invasive than the theft detection devices found at the doors of large stores. The scanner combines a sophisticated magnetometer with artificial intelligence (AI) algorithms to allow attendees to enter a venue without delay, while identifying firearms or other dangerous weapons. “The AI is taking those magnetic field signals and analyzing them, differentiating between innocuous objects and the threats we’re concerned about,” says Ellenbogen. “Is it a cell phone or a Glock? The scanner can quickly tell a weapon from something we all carry around every day.”

If the scanner spots a suspicious item, it shows up on a video display of the entry point, which is monitored by a person standing adjacent to the scanner. The AI will highlight the area where the potential weapon was seen — inside a backpack or in a front pocket, for example. The person would then be asked to step aside for a closer inspection, while other visitors can continue to enter the event uninterrupted. “Maybe it’s an eyeglass case or something, and you say, ‘Thanks and have a nice day.’ Or maybe grandma forgot she has the .38 in her purse,” Ellenbogen says. “If it’s a venue that doesn’t allow firearms, which most don’t, you say, ‘Sorry, you have to leave that in your car,’ or whatever the appropriate response is.”

Ellenbogen is now working with the city of Detroit to combat gun violence. “It’s not a particular venue they’re trying to protect. They want to have gun-free zones in the city,” he says. “Half the value of any of these systems is the deterrent effect that you get, which will hopefully convince people not to carry a gun into the area. The city can use our system in a lot of different ways to address gun violence.”