Officer Adam Brunclik was on patrol in Spooner, Wis. when he came upon a child in a moving shopping cart. He caught the whole thing on dashboard camera.
The runaway cart was just a few feet away from entering a busy highway. The officer quickly sped toward the helpless child.
"My immediate reaction was he was traveling fast, and so I knew there wasn't an option to stop the cart, but I had to do something to try to stop traffic because it was headed directly towards a busy highway," said Brunclik.
Brunclik acted right awaty. He said he turned on his emergency lights, drove on the highway to stop any oncoming traffic, ran out of his car and grabbed the little boy.
Police say the baby's mother was placing her other child in the car when the shopping cart with her baby rolled away. The baby was not hurt.
ABC News contributed to this report.