Witnesses say they saw mom violently dunk her three-month-old baby in a lake as her other child watched on

An Ohio mother has been arrested after witnesses said they saw a woman forcibly dunk her three-month-old baby into a lake.

Sharon Rose O’Hara, 39, was seen repeatedly hitting the ground with a car seat at Caesar Creek State Park on July 28 while the child was still restrained, shocked onlookers told police.

She then allegedly became even more aggressive when she took the car seat with the baby in it to the lake in the park and started throwing the baby into the water. WXIX Reports.

But to make matters worse, when police arrived on the scene, they noticed O’Hara had a nine-year-old child with him, police said. WKRC.

At one point, O’Hara even removed the baby from the car seat and began turning the child back and forth and dunking her under the water, prosecutors say.

Bystanders eventually ran over to stop O’Hara and protect the baby, while another called 911.

That child then told police that they had been treated poorly by their mother for days prior to the incident at the lake.

Sharon Rose O’Hara, 39, was arrested for allegedly immersing her three-month-old child in a lake

The incident reportedly took place on July 28 at Caesar Creek State Park in Ohio (pictured)

The incident reportedly took place on July 28 at Caesar Creek State Park in Ohio (pictured)

O’Hara was finally charged for the incident on Monday, with a grand jury report saying she “caused serious bodily harm to her three-month-old child and created a substantial risk to the health and safety of her 9-year-old child.” according to Law & Crime.

The mother was then arrested Tuesday and charged with three counts of child endangerment and one count of assault.

She is being held in the Warren County Jail as her children remain in the custody of a relative. The child’s current condition is unclear.