NORTH PLATTE — A 23-year-old Tryon woman has been sentenced to 12 to 24 years in prison for shaking her infant son in December 2018.

Shawlen F. Johnston, who pleaded no contest to an amended charge of first-degree assault last month, was sentenced Monday in Lincoln County District Court.

District Judge Michael Piccolo also handed her an 187-day term for violating her 18-month post-release supervision in connection to a forgery charge in early 2017. She was credited with time served.

The child, who was 7 months old at the time of the injury, suffered severe hematoma in his brain along with retinal hemorrhaging.

According to court documents, a doctor who treated the infant determined that the injuries were caused by shaking and was non-accidental trauma.

The child suffered seizures and his eyesight was damaged. Piccolo said the child will continue to deal with the results of the assault that will likely affect his ability to live a fully productive and happy life.

“You took that away from your child,” Piccolo told Johnston.

Johnston had pleaded no contest to the amended charge on Jan. 6. She originally was charged with intentional child abuse with injury.

Piccolo asked an emotional Johnston if she had anything to say before being sentenced, and she managed a short response.

“I’m sorry,” she told the court.

According to court documents, Johnston and a family member took the infant to the Great Plains Health emergency room Dec. 12. The child was soon flown to Children’s Hospital in Omaha.

In a conversation with law enforcement officials that day, Johnston said she believed that her 18-month old son had pulled the infant out of his bassinet and onto the floor while she had left the room to use the bathroom.

Johnston told authorities that the incident happened about 11 a.m. She did not enter the emergency room until noon.

“This was as close to a homicide as we are going to get,” Lincoln County Attorney Rebecca Harling said. “She waited an hour (to seek medical assistance). If she would have any longer, I’m not sure that we would be here today for anything else but a murder (case).”

Harling said she does not believe that Johnston has ever expressed true remorse for the incident.

Johnston’s attorney, Amanda Speichert, argued the opposite. Speichert said Johnston has expressed remorse in a number of conversations and has accepted responsibility for her actions.