A Florida mother has been arrested after her six-year-old son brutally pummeled her 13-day-old baby girl.

62-year-old Kathleen Marie Steele was charged with aggravated manslaughter and neglect for leaving the baby, likewise named Kathleen, in a vehicle with her two siblings while she went inside a cell phone repair store. While she was in there, the baby started to cry. That’s when the 6-year-old boy turned to violence.

He picked the baby up and dropped her on the floor of the vehicle, then slammed her around on various other surfaces there.

He admitted to authorities what he’d done.

He told them, “I took the baby, and I slammed her like this, and slammed her down, and pushed her up into the ceiling.” His descriptions that followed essentially had him throwing her around the vehicle like a ragdoll, according to the sheriff.

The sheriff said the baby’s skull was cracked, and she probably died while she was still in the vehicle.

Ms. Steele had left the children in there for over half an hour. Even once she left the store, she drove to Enterprise Rent-A-Car and spent another 30 minutes there before finally heading home…even after her son told her what he’d done.

When she arrived at home, she called a neighbor, a nurse, for help. That neighbor knew the baby was dead and called 911. The tiny child was taken to St. Petersburg General Hospital, where she was officially pronounced dead.

Her son, because of his age, won’t face charges, nor will law enforcement identify him.

The two boys are now separated and in foster care.