An Alabama man will not see the outside of prison gates for many years after “systematically” depriving his infant son of nourishment, authorities said.

Kristopher Matthews, 40, was sentenced to 20 years in prison this week for aggravated child abuse, 19th Judicial Circuit District Attorney CJ Robinson announced. Matthews was found guilty of the crime in August.

Karson Matthews was born in July 2018, weighing 6 pounds and 2 ounces, Montgomery NBC affiliate WSFA reported. However, two months later, he was taken to a hospital weighing “substantially less.”

The baby was found to have been denied nourishment and medical attention, “which ultimately led to the child’s death,” Robinson said. Karson’s mother, Shirley Matthews, was also convicted of aggravated child abuse and sentenced to 20 years in prison — with her fate being sealed in July 2024.

The district attorney shared his belief that the two-decade punishment was not enough for the parents, but that state law only allowed for 20 years to be the maximum punishment in a case like this.

“For everyone who thinks a 20 year sentence isn’t long enough, I 100% agree with you,” he said in a statement, acknowledging that they have since passed legislation to make the punishment more severe. “If this crime happened today, we could seek up to 99 years in prison for Kristopher and Shirley Matthews.”

Elmore County Circuit Judge Amanda Baxley, who handed down the sentence, agreed.

“This case is horrific and the jury’s message to me after the verdict was for all people connected to the death of this baby to be held responsible,” she said. “I wish I could sentence you to more than 20 years, but the law at the time of this offense handcuffed the prosecution and handcuffed me as well.”

“Thankfully, the legislature has updated the law to address situations like this and I appreciate them doing so,” she added.

Karson was the youngest of at least five children, authorities said. It is unclear who is caring for the rest of them.

According to the district attorney, after Karson’s death, Kristopher Matthews “admitted to having never taken Karson to the doctor after being released from the hospital after birth. He claimed he never personally fed his child and had no duty to do so since he was the father.”

Robinson then expressed how “evil” the crime was and how angry it made him feel.

“The photos in this case were worse than you would expect to see in a horror movie,” he said. “This withered child’s body was nothing but a dirty, skin-covered skeleton. A haunting image that no one who saw it will ever forget.”

“Kristopher and Shirley Matthews completely destroyed the life of their baby boy by neglecting his existence until he died,” the DA continued. “No question, this is one of the hardest cases we have ever had to prosecute. The suffering and agonizing death of this baby was completely avoidable.”

“Evil is real. Plain and simple,” he added. “Honestly, prison is too good for what they deserve, but it’s all the law will allow.”