A New York father has pleaded guilty to killing his toddler daughter, who was an eye cancer survivor, with a wooden baseball bat before burning her body and dumping her remains in an upstate waterway.

Ryan Lawrence, 25, pleaded guilty last week to first-degree murder in a plea deal with Onondaga County prosecutors.

Lawrence admitted beating to death his 21-month-old daughter Maddox outside Syracuse in February.

Authorities say he burned the girl's body in a fire pit, then tied the remains to a cinder block that he dumped in Onondaga Creek in Syracuse.

It was reported that Maddox had already beaten eye cancer before her father killed her. Photo / Facebook
It was reported that Maddox had already beaten eye cancer before her father killed her. Photo / Facebook

The child's body was found by police divers about 36 hours after an Amber Alert was issued for the missing child.

Authorities issued an Amber Alert for Maddox on February 21 after Lawrence disappeared with her.

Maddox's mother, Morgan Lawrence, told police her husband was supposed to pick her up from her job at the Destiny USA shopping mall the night of February 20 but instead left the car and keys for her in a parking lot.

When she returned home, Morgan Lawrence said, she found a message from him that indicated he might harm Maddox and himself.

She called police, touching off the Amber Alert and a massive search by several law enforcement agencies.

On February 22, police got a call from a thrift shop employee who recognised Ryan Lawrence in the shop in Baldwinsville, 16km northwest of Syracuse, authorities said.
Police found Lawrence walking on a nearby street, wearing a disguise, and took him into custody, they said.

He confessed and led authorities to his daughter's body, TWC News reported.

Maddox had already beaten eye cancer, CBS 5 reported.

Onondaga County District Attorney Bill Fitzpatrick told the station in February that "she had been fighting a very unusual form of cancer, and all indications were that she was successful.

"But it was expensive, the treatment, and it was time-consuming. If that contributed to her demise, I don't know."

Fitzpatrick told the station at the time: "Without going into too much detail, [Ryan Lawrence's] statements allude to almost a sense of jealousy about the attention that this child was getting, as opposed to the attention that he was getting."