The Boyd County Sheriff's Office charged John Elliott, Jr. with manslaughter.
Investigators say his 2-year-old daughter, Summer Adkins, died while in his care.
The girl's mother, Brittany Adkins, says the child was supposed to be with Elliott's sister.
She says the sister left the child with Elliott without her permission.
Adkins says she soon got a call that Summer was dead after spending the day alone with Elliott.
"Yes, and all he could say to me is, 'I didn't mean to do it, I'm sorry,' ” Adkins said.
The coroner says Summer died from compression.