It happened at the intersection of Route 9 and Route 24 near Bartonville.
The deputies' squad car was blocking traffic when the Illinois State Police say another driver, 53 year old Kevin Kerker, ran into the back of it.
All three people had minor injuries.
Illinois State Police say Kerker was cited for violating the move over, or Scott's Law.
The crash tied up traffic for more than an hour.
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