The department's post says the child "escaped his mother's watchful eye" and wandered along Route 59 as traffic whizzed by.
Dash cam from Sergeant Anthony Mannino's patrol auto shows him plucking a toddler from harm's way in Naperville, Illinois last month.
Naperville Police Sergeant Anthony Mannino has seen a lot in his 20-plus years on the job, but nothing quite like what saw while patrolling a busy highway several weeks ago.
Mannino tells CBS Chicago he first thought the boy was a stray dog.
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As a result of his role in the rescue, Mannino received the Naperville Police Department's Life Saving Award last week, according to the post.
No one was hurt, which the police department attributes to Mannino's "observation while on patrol and quick reaction, placing his squad auto and himself between the child and traffic". Police say he lived nearby and he was quickly reunited with his mother.
The video shows Mannino pull his cruiser up behind the boy and get out, chasing him down and yelling, "Hey, hey, hey, come here", then stopping him up and telling him "You're OK, you're OK".
"I have twin boys", he said.