The woman told 911 her breast milk had dried up and she needed baby formula.
So Corporal Hunter Willoughby went to a local Meijer grocery store, got them to open up, and bought formula and bottles with his own money.
Willoughby brought the items to the desperate mother and he refused to accept any payment, the department said on Facebook.
"You don't often hear about everything a police officer does in the course of their shift, but I do, and this is an example of the Miami Township Way," Chief Mike Mills said.