The mother of a toddler allegedly killed by his father in the Bronx says she plans to sue the New York City Police Department.

The body of 2-year-old Montrell Williams was found in the East River in June, over a month after he went missing. His father, 20-year-old Arius Williams, is charged with his murder after Williams allegedly threw Montrell off a bridge.

Montrell's mother, Cierra Carroll, claims police ignored her repeated calls for help.

"Nothing was done"

Carroll says on May 11, which was Mother's Day, Williams did not show up to return Montrell, so she called 911. She claims dispatchers misclassified it as a custody dispute.

Eventually, she says, a judge issued an arrest warrant, but Carroll accuses the NYPD of failing to execute it.

"We made several calls to 911, calls for the police, and nothing was done," said Carroll's mother, Octavia Roane.

Carroll says she found the boy's father weeks later at a nearby shelter and claims he admitted to throwing the boy in the water, and also threatened her with a knife. She alerted police, but says they were delayed in arresting him.

"I shouldn't have had to chase him down in order to find the child," Carroll said.

Carroll leaned on her mother for support as they both described Montrell.

"He was a happy child," Carroll said.

"He loved playing with his toy cars. He liked running around," Roane said.

"They asked for help repeatedly"

Standing outside the 40th Precinct in the Bronx on Friday, Carroll's attorney announced they've filed a notice of claim for $60 million against the City of New York and the NYPD for what they're calling Montrell's wrongful death.

Attorney Shiraz Khan says the women did everything they could.

"They called not once, multiple times trying to get help. They put them on notice that Montrell's father was a dangerous man. They put them on notice that this child is in danger. They asked for help repeatedly. No Amber Alert was issued," Khan said.

Activists are standing with the family.

"No amount of money will bring back Montrell," Rev. Kevin McCall said.

The NYPD said they will review the lawsuit "if and when it is filed." The department added that Montrell was murdered on May 10, and says the initial complaint was not reported to the NYPD until May 11.

Last month, the mayor said the police response was under review.

Williams, meanwhile, is being held without bail.