Multiple witnesses had called police about 30 minutes earlier and had reported seeing a woman throw the girl into the river. The child was rushed to the hospital, where she was pronounced dead.
According to Spectrum Bay News 9, authorities were notified of an emergency at the Hillsborough River along Columbus Drive on Thursday afternoon.
WFLA reported that witnesses told police Denson stole a auto from a vehicle lot, forced her daughter into the back seat, drove to the Hillsborough River, then dragged the screaming girl into the water and released her.
Shakayla Denson, 26, has been charged with first-degree murder in the death of Je'Hyrah Daniels.
Witnesses watched Denson, who also was screaming, clutch her daughter close to her chest and wade deeper and deeper into the river.
Upon entering the river, she threw Je'Hyrah in and walked away.
She said she didn't see a child, but thought something wasn't right.
Denson had recently sought help for her daughter who she said was on the autism spectrum.
Police say she fell over 60 feet into Tampa Bay, where a marine rescue crew discovered her body a short time later.
A K9 officer tracked Denson to a nearby street where Denson was arrested. ". they felt paralyzed by the whole thing".
In January 2015, a father allegedly threw his 5-year-old daughter off the Dick Misener Bridge in St. Petersburg. Witnesses saw her do it, investigators said.
The victim was identified as Je'Hyrah Daniels, 4.
"Witnesses report the child was screaming and at one time, both the child and the mother were screaming".