A 29-year-old Cheyenne man has been charged with aggravated child abuse after allegedly injuring his girlfriend's infant daughter in September of 2015.

Joshua Walter was arrested Friday and made his initial appearance in Laramie County Circuit Court today (Monday).

Court records say Walter and the child's mother took the girl to Cheyenne Regional Medical Center on September 13, 2015.

The child was transferred to Children's Hospital Colorado where the medical team diagnosed her as having non-accidental trauma with acute subdural hematoma, evolving secondary brain injury (HIE), severe bilateral retinal hemorrhage and forehead pattern bruises.

The child's mother reportedly told police that Walter had taken the girl into the master bedroom to take a nap. She said she heard a "thump", but didn't hear her daughter cry. When she went into the bedroom, Walter told her the child had fallen off the bed and landed face down in front of the dresser.

The child's mother noticed the girl had a bloody lip and a bump on her head. She also said her daughter's "head was very floppy" when she picked her up.

On the way to the hospital, Walter reportedly told the child's mother not to mention that he was at the home when the girl was injured.

During an interview, police say Walter admitted that he was the last adult in contact with the child prior to her injuries. He also admitted that the child's injuries were more severe than what could happen from falling out of bed.

If convicted, Walter could face up to 25 years in prison.