BOONE, N.C. (WBTV) – A man was charged with murder in the death of an infant and child abuse involving a separate child in Watauga County Saturday.

Watauga County deputies say they received a 911 call about an infant not breathing on Ray Brown Road in Boone around 11:47 a.m. Wednesday.RELATED: NC sex offender charged with murder in infant’s death

The infant went to Watauga Medical Center Emergency Department before being transported to Brenner’s Children’s Hospital in Winston-Salem, where the infant died on Friday.

Deputies say the other child involved in the incident was treated for serious injuries.

“I just don’t understand,” the infant’s mother, Rebecca Vamvaketisk, said Monday.

Twenty-four-year-old Ryan Neil Hicks, her boyfriend of the past three months, was babysitting for Vamvaketisk in the mobile home they shared when the 911 call was made.

“It came in as a baby not breathing,” says Watauga Sheriff’s Office Captain Dee Dee Rominger.

As a matter of routine, detectives went to the hospital where the child was taken. It did not take long for investigators to think it was no accident.

“I knew something was not right, yes,” says Rominger. The 10-month-old was transported to another hospital, his 3-year-old brother was treated for bruises.

Hicks was charged with negligent child abuse inflicting serious bodily injury in the case, second-degree murder and sex offender using social website. He is a registered sex offender, according to the North Carolina Department of Public Safety.

“I had no idea he was like this,” said Vamvaketisk, and added, “I’ve known this guy since he was in kindergarten himself.”

Vamvaketisk says she was aware of his past criminal record but also says she did not know enough about it. She said she wishes she had done a background check to learn what she called “the whole story.”

She advises other single moms to do background checks on anyone they date, including people they have known all their lives because “you never know.”

Vamvaketisk says DSS is also looking into her situation and while that goes on her older boy will stay with relatives. She says that Hicks has given her a couple of versions of what happened in the home but she says she wants “the real story” and made a plea to Hicks.

“Ryan, please just be honest with the court system and just tell them what you did,” and added, “It will make your life a whole lot easier if you just told the truth.”

Hicks was given a $1.1 million bond and is expected to appear in court April 6. Autopsy results are pending.Copyright 2017 WBTV. All rights reserved.