A father confessed to murdering his 2-year-old son, after the latter’s body was discovered inside a garbage bag by the police in an apartment in Little Village, Chicago.

The confession came shortly after Rolando Ortiz, 37, was arrested late Wednesday. He said he stabbed his son, Mateo Aguayo, to death because he was "very frustrated that he could not sleep," and his son was "running around and keeping him awake," ABC News reported. 

Ortiz grabbed his son and held him down as he slashed his neck with a kitchen knife, the police said. Aguayo suffered severe trauma from laceration and fatal stab wounds to his neck to the point of “near decapitation."

Chicago Police Detective Cmdr. Brendan Deenihan said in a press conference on Thursday that after he realized what he did, Ortiz tried to kill himself by cutting his wrist. However, he changed his mind and proceeded to place the toddler’s corpse in a garbage bag.

Next, Ortiz tried to call up his wife and confess his crime but he could not reach her. He did manage to reach his wife’s sister, whom he told everything to, Fox News reported. 

Upon hearing his story, Ortiz’s sister-in-law contacted other members of the building and told them to check on Ortiz. They found the father with a bleeding wrist, and the garbage bag with Aguayo’s body inside. As witnesses called 911, Ortiz fled from the scene of the crime.

He was arrested nearly 50 miles away in Kankakee County, following a traffic stop by state police and the FBI, and was "immediately" brought back to the Chicago area. According to authorities, he might have been trying to flee to Mexico.

Ortiz was charged with one count of felony first degree murder on Wednesday.

"This is the kind of slaying that keeps police officers up at night," Chicago Police Superintendent Eddie Johnson said during the press conference. “Mateo wasn’t old enough to make a bad decision. Mateo wasn’t old enough to take the wrong path in life. He was just an innocent kid whose trust and safety was betrayed by the one man he should never have to question. His father.”

Ortiz does not have a criminal record in the Chicago area. He has never been accused of harming any of his other six children. Aguayo was Ortiz’s youngest son.

The gruesome tale of Ortiz’s crime has shocked the neighborhood.

"I have kids of my own and I mean it's heartbreaking to hear something like that to a 2-year-old," said neighbor Jairo Cholico, ABC7 reported. "Heartbreaking, just to know it happened on your block."

"It's very devastating. Very sad for anybody, any age to be murdered of anything. So I'm just devastated," said Quenshoda Howard, another neighbor.

A small cross bearing Aguayo’s name and a basketball next to it was placed in front of the apartment where Ortiz lived. People who have never interacted with Ortiz or his family placed stuffed animals, balloons and other mementos near the cross.