Melody Pheng, 2, was killed in her Sunset Park home, police said. View Full Caption DNAinfo/Valeria Ricciulli

SUNSET PARK — A mother was charged in the murder of her 2-year-old girl in their Sunset Park home Sunday after the child's death was ruled a homicide by the Office of the Chief Medical Examiner, police said.

Lin Li, 24, was charged with second-degree murder, manslaughter and acting in a manner injurious to a child for the death of Melody Pheng, according to police.

Investigators began digging further into the case after bruise marks on the neck of the toddler's brother cast doubts on Melody's father's claim that she accidentally drowned, sources said.

Melody was found unconscious in her family's home at 652 47th St., near Seventh Avenue, about 8:26 p.m. Sunday, officials said.

Her father was trying to resuscitate her with CPR before emergency responders brought her to Maimonides Medical Center where she was pronounced dead, police and reports said.

The city's medical examiner looked over her body Monday, but was not able to determine the cause of death until Tuesday morning, a spokeswoman said.

"The cause of death is drowning. The manner of death is homicide," said Chief Medical Examiner Dr. Barbara Sampson.

Li was formally charged Tuesday afternoon. Melody's father had not been charged as of Tuesday evening, an NYPD spokesman said.

Neighbor Jose Ochoa, 69, said he never thought the mother was capable of violence.

"I think that it was an act of desperation, because she didn't seem abusive," Ochoa said. "The last time I saw them was on Saturday when they were going to do laundry. The baby was adorable."