An Indiana man has been arrested and charged in connection with the death of his girlfriend's 21-month-old daughter, authorities said. The Dearborn County Prosecutor's Office announced Jesse Sartin, 25, faces counts of murder and aggravated battery resulting in death after the toddler succumbed to injuries sustained while she was under his care, as reported by WRTV.

According to court documents, the incident occurred on July 24, when Sartin was babysitting the child while her mother was at work. The girl was later taken to St. Elizabeth Hospital Dearborn exhibiting a "suspicious head injury," prompting an investigation by Lawrenceburg police officers. It was initially reported as an accident, however, upon further investigation, authorities allege that Sartin shook the child for approximately 20 seconds, WLWT describes.

Sartin, who is not the biological father of the girl, had reportedly told authorities she fell after a dog knocked her off a stool. But court records show discrepancies in Sartin's account of the events leading to the injuries that were "not consistent with the story given," according to FOX19.

A letter Sartin wrote to the child's mother after the incident offers a different narrative, it describes a struggle trying to remove the toddler from a bath, "I tried to pull her out but she kept pulling away and I was getting upset. Baby, I’m so upset. I shook her trying to get her to calm down," Dearborn County Detective Jeremy Shepherd read from the letter during court proceedings, as witnessed by FOX19. This revelation has added a disturbing layer to a case that has shocked the community.

The final outcome of the case remains to be seen as the legal process unfolds. Sartin's charges are severe, and if convicted, he could face significant time behind bars for the tragic, untimely loss of an innocent life.