An Alabama man will remain behind bars for many years after authorities stated he “systematically” starved his infant son.

Kristopher Matthews, 40, received a 20-year prison term this week for aggravated child abuse, according to an announcement by 19th Judicial Circuit District Attorney CJ Robinson. Matthews was convicted of these charges in August.

Karson Matthews, born in July 2018, weighed 6 pounds and 2 ounces at birth, as reported by Montgomery’s NBC affiliate WSFA. Just two months later, he was hospitalised, weighing significantly less.

The infant was found to have been deprived of necessary food and medical care, leading to his death, said Robinson. Karson’s mother, Shirley Matthews, was also found guilty of aggravated child abuse and handed a 20-year sentence, which will be finalized by July 2024.

The district attorney expressed his view that a 20-year sentence was insufficient for the parents, noting that state legislation limits the maximum penalty to 20 years for such cases.

“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.”