Officers reportedly became aware of the assault after they were notified of the boy’s severe injuries by doctors at Vanderbilt University Medical Center Tuesday afternoon.
Porter was added to the TBI’s “Top 10 Most Wanted” list last week and has been on the run since Tuesday.
The TBI offered a $2,500 reward for his location and capture.
Lawrenceburg Police Lt. Blake Grooms said, “I can’t even express it. I’m not even a parent, but when someone tells me that a 16-month-old child has been maliciously and intentionally hurt, words cannot describe it.”