CHICAGO (CBS) -- Summertime in Chicago is electric – festivals, fireworks, the lakeside breeze providing a sweet escape from the steamy pavement.
But beneath it all runs a current of crime, and law enforcement is working hard every day to zap that crime out.
One means of fighting that crime that you have likely heard about is LPRs - or license plate readers. Recently, CBS 2's Sabrina Franza rode along for a shift with Illinois State Police to see those LPRs in action.
Armed with bulletproof vests and some camera equipment, Franza suited up and got in the passenger side of a state police squad car with ISP District Chicago Capt. Dave Keltner. The feels-like 100-degree June day involved a lot of stolen vehicle incidents.
The shift began at 7 p.m. As Franza sat in the passenger side of an ISP cruiser, Keltner explained how state police know they have a hit on a license plate reader.
"If they've been entered into any of those software packages, then our officers will end up getting postings, pictures, still frame stuff with locations," Keltner said.
In one incident before dark, Keltner and Franza heard the license plate reader detect something. There was a stolen car on the road on the Dan Ryan Expressway.
A police plane used the license plate to spot the car. They told Franza and Keltner where to go.
The drivers ditched one car for another – and then a third, and it looked like police might have lost them. All that car swapping might seem like a problem for LPRs, but it turns out it doesn't matter that three different cars with different license plates are involved.
LPRs don't need a plate to track a car at all.
"It's not just plates," Keltner said. "We can search – there's various avenues for us to search for make, models, and anything else that's in the area."
The last car in that sequence of swapping, a white Mercedes, was eventually boxed in and cornered. Busted.
"Without other resources, it makes it very difficult," Keltner said, "but when we're able to utilize unmarked cars, we're able to utilize air support, we're able to use various cameras to be able to access some of that information, it makes it easier for us."
Illinois State Police have 190 functioning state-owned LPR cameras. The plan is to install 300 total.
They also use information from another 150 that they share with the City of Chicago and other neighboring jurisdictions.
Still, that is only have the readers ISP said they would have up by this point. And Chicago has an estimated 118 miles of expressway – a lot of ground to cover.
So is 300 cameras going to be enough?
"My opinion is we're doing some great work, and we're maximizing everything that we have," Keltner said. "Could more always help? Yeah."
During Franza's ride-along shift, state police recovered at least eight cars – which are to be returned to their owners.
In another bust at 10:25 p.m., state police used LPRs to track down a stolen car from the Dan Ryan to a Citgo station at 63rd Street and Yale Avenue and recovered a gun. A male juvenile driver was arrested and faces weapons and stolen vehicle possession charges.
But the stolen cars state police recover just scratch the surface of solving crimes. What is inside the cars tells an even bigger story.
Backpedaling a little earlier in the shift at 8:20 p.m., a City of Chicago LPR had picked up information about a car that was believed to have been taken in a carjacking.
Franza and Keltner followed the Infiniti down the Dan Ryan to a residential driveway in south suburban Dolton. Four suspects fled, but a juvenile suspect was apprehended and now faces multiple charges.
In the Infiniti, there were five guns and one rifle. They were on the street illegally, and thanks to state police, they're now toast.
"Probably few and far between that we're not recovering weapons with the stolen vehicles," Keltner said.
And then there was the biggest case of the night, which went down at 11:30 p.m.
An LPR picked up a Range Rover a group of suspects had taken. The suspects then ditched the Range Rover for a white van.
There was a treasure trove of clues from other crimes inside.
The van skidded up and down the Dan Ryan, took a joy ride onto DuSable Lake Shore Drive, and crashed into another vehicle containing a family who were just minding their own business.
Five men were arrested – out of breath and out of options.
And for the second time in one night, what was inside the vehicle revealed even more clues. There were burglary tools in the van.
The tools and the plates solved more than one crime – again. The drivers were suspected burglars who had targeted the BNSF Railway. It was the end of the line for them – and then end of the shift for Franza and Keltner.
As officers arrested the suspects in the van, the LPRs went on watching over the roadway – silent, but ready to pounce at a moment's notice, and at a time when tech needs to supplement manpower.
Franza asked Keltner if the LPRs help make up for the fact that the number of people joining or staying in law enforcement has decreased.
"I think every department sees a diminishing of their numbers just by sheer attrition and lack of hiring - so yeah, the steps here does take up some of the slack, if you will," Keltner said.
Altogether, Chicago's streets are made safer with police collaboration, and a few cameras that can track those thin pieces of metal with letters and numbers that are mounted on every vehicle.
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