A live-in boyfriend has been charged in northwestern Minnesota with inflicting deadly head and neck injuries to a 22-month-old girl, whose mother told authorities that the defendant pleaded for her to stand by him, even though she also had been physically abused by him.

Raul Perez, 24, of Dilworth, Minn., was charged Wednesday in Norman County District Court with two counts of unintentional second-degree murder in the Aug. 31 death of Ariel Reyes, of Ada, Minn. Perez remained jailed ahead of a court appearance Friday.

Soon after Ariel's death, the child's mother told police of several months of abuse at the hands of her boyfriend, the criminal complaint said. The abuse included the mother being lifted off the floor by her hair and being burned on her arm with a cigarette lighter.

Under police questioning, Perez denied shaking or striking Ariel and added that he also has never harmed his three young boys, the complaint read.

According to the criminal complaint:

Shortly before noon on Aug. 29, medics were called to the home in Ada and saw Perez attempting to revive Ariel with mouth-to-mouth resuscitation. She remained unresponsive and died two days later at a Fargo hospital from what the medical examiner determined to be head injuries and other wounds.

Perez was looking after Ariel and her 5-year-old brother while his girlfriend was picking up groceries and putting gas in her vehicle.

After paying for the gas, the mother saw Perez running down the street toward her, holding her son and saying that Ariel had stopped breathing and an ambulance had been called.

A doctor at Sanford Medical Center noted many injuries to Ariel, including bruises to her jaw, forehead, thigh, shoulder and the base of her spine. Also diagnosed were numerous severe brain injuries and bleeding at the back wall of an eye.

At the hospital, according to the mother, Perez said he didn't want to go to prison and leave his three boys behind.

"No matter what happened," the mother recalled Perez saying, "you promise me you won't turn your back on me."

Perez told police that Ariel said something that morning he couldn't understand and didn't appear right. He said he picked her up to get her to stand and she fell motionless, prompting him to try resuscitating her.