04/16/2012 05:47 pm ET Updated Apr 16, 2012

Armaney Cotton, 2-Year-Old Found With Bites, Scratch Marks, Dies In Hospital (VIDEO)

Updated story

A 2-year-old Chicago girl who was brought to the hospital with bruises, scratches and bite marks died of her injuries, and now her family is looking for answers.

Armaney's mother, Brittany Cotton, 19, says her boyfriend of two years was watching her daughter while she worked, as he had several times previously, WGN reports. Later that day, Cotton received a phone call informing her that her daughter had been pronounced dead after coming in with bruises and other signs of abuse.

The boyfriend, Devell Johnson, 23, of the 5500 block of South Emerald Avenue, was charged Monday with first-degree murder in Armaney's beating death, the Chicago Tribune reports. He is expected to appear in court Tuesday, according to NBC Chicago.

"He has never harmed my child, never," Cotton says of Johnson (See video above). "He has never disciplined my child, because I wouldn't allow it. He wouldn't even ask to discipline her. So it's just eating me up inside, because I need to know what happened."

An autopsy was performed Sunday, and found that the toddler's death was caused by multiple injuries from a beating, NBC Chicago reports. It also identified the bite marks on her skin as human. Her death was ruled a homicide.

The state Department of Child and Family Services says they have had no previous contact with the family, but are investigating abuse allegations against the boyfriend, according to CBS.

Armaney's grandmother, Denise Cotton, told the Chicago Sun-Times that the child's sudden death is difficult to process.

"She came and waved at me and said 'bye-bye,'" Cotton told the newspaper. "I never thought that was a permanent bye-bye."