Authorities say the son of 29-year-old Christopher Gregor died back on April 2, 2021, in Stafford Township, New Jersey.
At the time, it was determined that the boy sustained injuries due to blunt force trauma.
Gregor was charged with endangering the welfare of a child on July 7, 2021, and was later released from the Ocean County Jail.
On March 3, 2022, authorities determined the boy died as a result of blunt force impact of the chest and abdomen and the manner of the death to be homicide.
Gregor was arrested on March 9 on charges of murder.
"Today is the first step in bringing the person we believe is responsible for this young boy's death to justice," said Ocean County Prosecutor Bradley D. Billhimer. "This truly was a team effort, and I'm grateful for the determination and resolve exhibited by all the agencies involved."
Gregor is currently locked up at the Ocean County Jail pending a detention hearing.