TULSA, Oklahoma - Twins at the center of a child abuse investigation remain in a hospital but have a good prognosis despite multiple broken bones, according to Tulsa Police.

Their parents, meanwhile, remain behind bars.

Police say one improvement is that the most seriously injured baby will not need brain surgery, and is recovering from injuries that could be from a severe shaking.

The babies are named Benji and Cruz and were born December 13. They were small, and stayed in the hospital until just after Christmas, the 28, say police.

Their mother Clorinda Archuleta and the father Josh Wray posted pictures on Facebook with the babies, but by January 16, they were having mug shots taken at the jail, where they were booked for child neglect.

Detective Danielle Bishop of the Tulsa Police Child Crisis, said, "The extent and the number of injures, I can't think of another case I've worked that hasn't been a fatality that has had this number of broken bones and other injuries."

Archuleta took one of the babies to Saint Francis Hospital last Thursday, but police believe his injuries, including a broken arm, broken legs, rib and skull fractures, had happened several days before.

His twin has skull fractures and retinal hemorrhaging.

Detective Bishop said while police don't know exactly what happened; the injuries are similar to cases they've seen before.

"Shaken baby, you've got rib fractures from the grab, and they will shake them and throw them down in the crib, the rib fractures are from the grab, the retinal hemorrhage and the brain bleed is from the actual shake and the skull fractures can be from the impact of being thrown" Bishop said.

There are plenty of people offering to adopt the children, but police say only qualified foster parents could do it, and in this case, they won't go outside the family.

"There are family members on both the maternal and paternal side who would be considered great placements for the children through DHS," said Bishop.

Police have wrapped up the investigation and will send the case to the district attorney soon. The parents are being held on $100,000 dollars bond each.