We're hearing for the first time from the family of two children who were victims of a heinous sex crime.
The victims are an 11-month-old girl and a 5-year-old boy.
The attack was so violent both victims required surgery.
Nathan McKinney, 30, of Oklahoma City was arrested on two complaints of rape by instrumentation.
"I think I would just tear into him right now," Sandra McDaniel said, the grandmother of the young victims.
That's quite a contrast to how McDaniel felt toward her daughter's boyfriend before last Thursday.
She never imagined that McKinney would be charged with sexually abusing her two grandchildren.
"The only thing I can say is that a monster came from his soul and I don't know how anyone could do this to any children," she said.
McDaniel said the kids were in McKinney's care last Thursday at his northwest Oklahoma City house because her daughter was at work.
She said her daughter came home to discover her little girl's bottom was bruised.
Court records show that at Children's Hospital, the infant had a "laceration" near her bottom, bruises to her face and genitalia and a "foreign object had been lodged" inside her, which had to be surgically removed.
The boy "had an intestinal tear," which a doctor said was caused by "something being inserted" inside him as well.
The boy told the doctor McKinney hurt him.
"It's just horrible," McDaniel said. "My daughter has just fallen apart, as am I."
Sheree Powell, a spokesperson for the Oklahoma Department of Human Services, said abused children can get help at Child Advocacy Centers.
"We can help children who've been through traumatic instances like this," she said.
She's referring to specialists who know how to counsel and forensically interview a child without causing further trauma.
That service for victims is provided at no cost.
"We know that the earlier we can get in to help a child, the better off they're going to be later on," Powell said.
McDaniel still worries about long-term psychological scars.
"Since both of them have scars from surgeries and everything, that's going to be with them for the rest of their lives," she said.
McKinney was booked at the Oklahoma County Jail Friday on a $100,000 bond.
Charges have yet to be filed because the investigation is ongoing.
The family is working to set up a fund to help with medical expenses.