CHICAGO HEIGHTS, Ill. (CBS) -- It's a dangerous trend – armored truck robberies on the rise.
But an ambush in Chicago Heights on Tuesday ended differently than the thieves may have expected – with one of their own getting hit by the very truck they were targeting.
The robbery occurred in the parking lot for the store at 1333 Western Ave. in the south suburb. As CBS 2's Sara Machi reported, the Food 4 Less was back open Tuesday night after the violent attack, which happened early in the afternoon.
Key evidence lay around the parking lot late Tuesday, as investigators dropped an evidence marker over a shell casing. Rolls of coins also lay on the asphalt, and a Loomis armored truck was parked at the scene with a front wheel well missing.
The FBI said hours earlier, three men in their 20s robbed the armored truck at gunpoint. In a turn of events that was caught on video, of the suspects was hit by the armored truck in the process and may be injured, the FBI said.
The suspected getaway vehicle – a dark-colored Nissan sedan – was also hit by the armored truck and was severely damaged on its rear passenger-side door.
It was unclear who was driving the truck in the video but investigators from the FBI and Chicago Heights Police sharing the video – and are offering $20,000 – to combat escalating armed robbery numbers.
"You're right about armed robberies going up, yes" said Loyola University Chicago psychology and criminology professor Arthur Lurigio. "In Chicago, yes. And it appears nationally, yes."
Lurigio profiles armed robbers.
"Armed robberies can result in aggravated batteries, attempted murders, and homicides," he said, "so you have to expect that an offender who does an armed robbery is capable of shooting the person being robbed."
We've been showing you how bold and dangerous these robberies can be.
, three armored trucks were held up at gunpoint – each a few hours apart – in Chicago's Bridgeport neighborhood and in the south suburbs.
, a suspected thief grabbed bags and ran from a Brinks truck in Orland Park.
, an armored car guard was shot and hit in the bulletproof vest in Chatham.
Lurigio said each completed ambush could serve as inspiration for future attacks.
"If they're getting away with these types of activities or with impunity, that might embolden other people who are willing to do that," he said.
But it's unlikely that video of a thief injured in the act, as was the case Tuesday in Chicago Heights, would hold as much power as a deterrent.
The FBI said the robbers' getaway car had no license plates, but did have a dealer advertisement with a star and blue lettering.
Anyone with information should report tips to the FBI at (312) 421-6700, or to tips.fbi.gov.
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