A man accused of violently shaking his 7-week-old daughter pleaded guilty Monday.

Robert Elwin Elliott III was charged with aggravated child abuse for shaking the infant in 2014. Limestone County District Attorney Brian Jones said the case has been pending since then because Elliott was in jail in other jurisdictions.

Elliott returned to Limestone County in September, Jones said. Elliott submitted a guilty plea before jury selection began Monday.

Limestone County Circuit Court Judge Chadwick Wise sentenced Elliott to 18 years. Jones said he will serve the majority of that sentence.

“This particular case was difficult for everybody involved,” Jones said.

Investigators said the baby almost died as a result of the incident, suffering internal injuries, a cracked head and cerebral bleeding. Jones said the child, who is now 4, is making breakthroughs in the healing process. The family hopes the child will have “some type of recovery” from the incident.

Jones said many people shake their babies out of frustration or to calm them down without understanding the dangers, and he wanted the case to be a reminder to everyone how serious shaken baby syndrome is and how delicate a child is.

“The medical testimony was indisputable that this child had suffered horrific injuries to its brain and two different areas and injuries to the legs,” he said.