CHICAGO (WLS) --CTA passengers are now subject to random screening for explosives at train stations across the city.
There is no known threat to the CTA, but Chicago police said the precautionary measure is another layer of security. The screenings went into effect Monday morning.
The Multi-Mode Threat Detector is capable of finding trace amounts of explosive compounds, officials said. A team of CPD transit officers will work at one CTA station a day with the machines.
A random number of people will be selected each time. For example, if that number were 10, every tenth person would be approached by an officer and the outside of his or her bag would be swabbed. That swab is then read by the Multi-Mode Threat Detector for the presence of any explosive residue.
Some CTA passengers are concerned about being delayed.
"What if someone has to go to work and they're in a rush and they don't have time for you to swipe your bag or whatever?" Diamond Marshall, CTA rider, said.
"It does feel like an invasion of privacy. I would be insulted. Do I look like someone who carries a bomb?" Kathy Barthold, CTA rider, said.
The screening is voluntary, but passengers who refuse to have their bags swabbed will not be allowed on the train. Those who still try to get onboard after saying no to the screening are subject to arrest.
Chicago police said the process takes less than a minute and shouldn't have an impact on travel time.