A Louisiana man has been charged with first-degree murder after his infant son was found dead with multiple stab wounds over the weekend.

Fabian Miguel Smith, 33, of Zachary, is also charged with second-degree cruelty to a juvenile, according to the Baton Rouge Advocate. Smith remained in the East Baton Rouge Parish Jail Monday morning, accused of killing Jericho Smith, 11 months old, Saturday afternoon.

Zachary police Chief David McDavid said during a Sunday news conference that the baby suffered stab wounds across his forehead and had signs of blunt force trauma to the back of his head, the Advocate reported. Jericho was pronounced dead at the scene.

WAFB in Baton Rouge reported that police were called to the scene around 1:45 p.m. Saturday after two older children sought help from a neighbor. McDavid said that Smith, who was the only adult in the home at the time of the slaying, had locked the other children out of the house.

When they were allowed back inside, they found their brother. The children, ages 9 and 5, ran next door for help, McDavid said.

One of the neighbors went to the family’s home, where he found Jericho lying on the floor in a pool of blood.

“Call 911. I done messed up,” the neighbor quoted Smith as saying, according to McDavid.

The police chief said that Smith would not speak to officers who responded to the neighbor’s 911 call, but one of the children, still next door, screamed, “The baby is dead.”

>> Read more trending news

The motive for the slaying has not been determined, McDavid said. The knife believed to be used in the crime, as well as a gun, were recovered from the scene.

An autopsy was anticipated to shed light on whether the gun was also used in the homicide, McDavid said.

Neighbor Brent Waldon told the newspaper it was his nephew who the 9-year-old boy approached for help. Waldon’s wife, Robyn Waldon, said Smith seemed unaffected in the aftermath of the stabbing, sitting outside the house smoking a cigarette as investigators searched the property.

His 5-year-old daughter screamed and cried for about an hour, Robyn Waldon said.

“This is just a nightmare,” Robyn Waldon told the newspaper. “I’ve held that baby before, and our 7-year-old would go over and play there a lot. I just can’t believe something like this would happen so close.”

McDavid said that the case was an especially tough one for his investigators.

“This is the senseless killing of a little child of God,” McDavid said during the news conference.

The chief said the slaying greatly affected the officers, firefighters and other first responders who went to the scene.

“To see this, it just broke their hearts. All of them have small children,” McDavid said. “I have grandchildren and children myself. To see this, it’s just senseless to see this happen in Zachary.”

Jimmicka Bouie, who identified herself as Jericho’s maternal aunt, set up a GoFundMe page to help her sister, Iesha Tolbert, pay for the baby’s funeral. The page does not address how the baby died, but calls the incident a “tragic accident” that ended in his death.

As of Monday, the page had raised about $1,150 of its $5,000 goal.