Chris McLaughlin, a vice president with Evolv Technology, test the company's body scanner at Union Station subway station in Los Angeles Wednesday, Aug. 16, 2017. Passengers boarding subway trains in Los Angeles may soon be shuffled through airport-style body scanners that are aimed to detect firearms and explosives. A two-day pilot program by the Los Angeles Metropolitan Transportation Authority, Metro began Wednesday at Union Station. Officials say the machines can scan about 600 people per hour. (AP Photo/Mike Balsamo)

Passengers boarding subway trains in Los Angeles may soon be shuffled through airport-style body scanners that are aimed to detect firearms and explosives.

A two-day pilot program by the Los Angeles County Metropolitan Transportation Authority began Wednesday. But officials quickly experienced a hiccup when a scanner being demonstrated Wednesday morning at Union Station malfunctioned before passengers could be put through the machine.

The machines use sensors to scan a person as they walk through, searching for firearms and explosive compounds, said Dave Sotero, a Metro spokesman. Passengers don't need to unload laptops or take off their jackets or shoes as the radio waves scan them to detect anomalies.

"It is specifically designed to test for mass-casualty threats," Sotero said. "The technology enables the system to locate on the body where there is a potential threat, and it appears on a video screen."

Metro is conducting the pilot program to evaluate the accuracy and capacity of the portable machines and determine if the scanners could become permanent fixtures in the Los Angeles transit system.

Each machine is designed to scan about 600 people per hour, Sotero said. About 150,000 passengers ride on Metro's Red Line daily, he said.

Los Angeles Metropolitan Transportation Authority, Metro hold a two-day pilot program of new body scanner at Union Station in Los Angeles Wednesday, Aug. 16, 2017. Passengers boarding subway trains in Los Angeles may soon be shuffled through airport-style body scanners that are aimed to detect firearms and explosives. Officials say the machines can scan about 600 people per hour. (AP Photo/Mike Balsamo)

"This is designed so you don't have to wait," Sotero said. "The idea is that you have a continuous flow of people through the security system without causing a backlog and causing people to miss their trains."

Similar to airport checkpoints, when someone passes through the scanner, they are held for a few seconds while law enforcement officers watch a monitor that shows the location on any anomalies the body. Several security officers stood guard at the screening checkpoint at Union Station on Wednesday morning. Large signs advised passengers that the screening is voluntary.

The scanners sell for about $60,000 each, said Chris McLaughlin, a vice president with Evolv Technology, which makes the system.

"I think it is a good idea with everything that has been going on and ISIS," passenger Jazmin Rosales, 29, said. "As long as it doesn't take too long, at least you know you can feel safe."

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