THREW KID BRO TO HIS DEATH

Mentally ill man told cops he killed boy, 4

A mentally ill Brooklyn man who flagged down cops early Saturday to report his kid brother was hurt quickly confessed to more: The 4year-old was dead — and he was the killer, cops said.

Shawn Smith, 20, was charged with murder for tossing little Shimron Smith from the roof of their sevenstory apartment building to his death in the concrete courtyard below, police said.

The little boy’s broken body was found after his panicked older sibling flagged down a police car outside their Flatlands apartment.

“Can I speak to you?” a high ranking police source quoted Shawn Smith, 20, as asking the officers. “I need to tell you something.”

When the cops asked if he could wait while they handled another call, Smith sat patiently until he was told to speak.

“I think my brother’s hurt,” he said. “Take me there and I’ll tell you more.”

The officers directed fellow cops to the Nostrand Ave. building, where the tiny victim’s body was found around 3:30 a.m., flanked by discarded trash bags and a stroller.

Neighbors reported that a loud boom broke the silence in the middle of the night.

Smith was taken into police custody after cops made the grisly discovery.

“It’s very inhuman. Too inhuman,” said John Okoh, whose family lives in the building. “They ought to have controlled the person who is sick.”

Residents recounted seeing the older brother, who has a history of schizophrenia, aimlessly walking up and down the building steps.

The older brother was “a little off, for the most part,” said one neighbor in the building. “You can kind of see when a person is off.”

The dead child, in contrast, was remembered as bright and outgoing.

“He was a very playful little boy,” said the same neighbor. “He’d play outside, riding a bike. Just playing with family members.”

A building worker, who asked for anonymity, said the boy was tossed from the roof. And a surveillance video reviewed by the NYPD shows Shimron’s older brother, identified by residents as Shawn, taking the child up one flight of stairs from the sixth floor to the top floor.

“They can’t see him going off (the building), but they can see them going up and (Shimron) falling,” the worker explained.

A 4-year-old boy was found dead in a rear courtyard on Nostrand Ave. near Ave. J in Brooklyn early Saturday. The boy’s older brother Shawn Smith (inset) told cops he threw the boy off the roof of their seven-story building.