A Tennessee man beat a 4-month-old boy to death earlier this month after finding out the child was not his son, authorities said.

Jose Avila-Agurcia, 33, of Memphis, is charged with first-degree murder in perpetration of aggravated child abuse in the death of Alexander Lizondro-Chacon. He believed the infant was his throughout the mother’s pregnancy, according to court documents obtained by Commercial Appeal newspaper.

The child died April 12 from blunt force trauma as a result of injuries to his ribs and had a fractured skull, the paper reported. Avila-Agurcia and the boy’s mother, Mercy Lizondro-Chacon, initially told police they didn’t know how Alexander was injured, a report said.

CLICK HERE TO GET THE FOX NEWS APP

On Tuesday, she allegedly told investigators that Avila-Agurcia admitted to punching her son multiple times in the head after learning he was not his father. He was arrested hours later.

He is scheduled to appear in court Thursday.