PARKER, S.D. (KELO) — When someone pleads guilty to first-degree manslaughter, they face up to life in prison. But a Parker man who killed a 4-month-old baby in 2022, received just a fraction of that time.

It was here inside a Parker home on September 4th, 2022, where 26-year-old Phillip Delaney killed his partner’s 4-month-old baby boy.

“This is an infant, whether it’s his child or not, he took that life,” said Attorney General Marty Jackley.

Court documents say Delaney became overwhelmed and frustrated as the baby was crying, picked him up and shook him three or four times before the baby went silent.

According to a statement signed by Delaney, he called 911. The infant was treated but passed away as a result of his actions.

According to an autopsy, the baby died of a traumatic brain injury due to a non-accidental injury inflicted by an adult.

“Because of the autopsy primarily, as well as some of the witness statements, we came to the conclusion that this was a shaken baby case, that would best fit, first-degree manslaughter,” Jackley said.

Delaney was originally charged with murder, manslaughter and aggravated battery of an infant. He pleaded guilty to first-degree manslaughter, which has a maximum sentence of life in prison.

Today a judge sentenced Delanley to 6-years. When you subtract the time he’s already spent in jail, he’ll spend just 4-and-a-half years in prison

“The state had requested a more significant sentence- a 50 year sentence- but appreciating that there were some mitigating circumstances, the defendant did not have a criminal history. There was continuing relationship with the victim’s family that were factored in by the court,” Jackley said.

The Attorney General’s office worked with Turner County officials for both the investigation and the court case.