The medical examiner ruled Sofia Marie Echevarria died from blunt force trauma to the head

Sofia Marie Echevarria
Sofia Marie Echevarria
| Credit: Gofundme

Authorities in Ohio investigating the beating death of an 18-month-old girl have charged the boyfriend of the child's mother with aggravated murder, PEOPLE confirms.

According to online records, Devon Mallory, 31, is being held on $1 million bond following his arrest this week.

WOIO and reports Mallory is accused of killing his girlfriend's daughter, Sofia Echevarria, who died late last month.

Sofia died on July 30, five days after the alleged attack.

According to the reports, which cite Mallory's arrest report, the suspect was babysitting Sofia on July 25, along with two other children.

Sofia's mother was at work at the time.

Police allege Mallory called his girlfriend at around 5 p.m. that evening, and said Sofia was unconscious and breathing abnormally. He also called 911, and the ambulance pulled up to the home just as Sofia's mother arrived.

Mallory allegedly told police Sofia was playing with the older children when she fell and hit her head on a Nerf gun, according to the reports. He said he was not in the room when the alleged incident occurred.

However, Mallory's story doesn't appear to match up with the findings of the autopsy of Sofia's remains.

The medical examiner ruled her death a homicide from blunt force trauma to the head.

According to the reports, Sofia suffered severe brain bleeding. Doctors determined her injuries were not accidental, and likely the result of a brutal attack.

Police allege Mallory was harsh with Sofia, disciplining her whenever she'd cry.

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In February, Mallory also pleaded guilty to assault after being accused of pushing the mother of his 3-year-old son down a flight of stairs, according to The woman, who was walking up the stairs on crutches after a fight, broke her wrist; Mallory was sentenced to one year on probation in that case.

At this point, Mallory has yet to enter a plea to the single charge against him. Online records fail to indicate if he has retained legal counsel.