The toddler brother of the 7-month-old Brooklyn girl killed while sitting in her stroller was hit by the same bullet that took his sibling’s life — as cops reveal that a person of interest in the case will be hit with murder charges.

Amuri Greene, 21, is expected to be charged in the Wednesday afternoon shooting that left little Kaori Patterson dead and her 2-year-old brother with a back wound, NYPD Commissioner Jessica Tisch said.

Greene, who has no criminal record but is a suspect in recent robberies, has been held as a person of interest since showing up at a local hospital for a leg injury shortly after the shooting.

He will be charged with murder and two counts of attempted murder for the daylight gun violence, cops said.

Sources said cops are investigating if Kaori’s dad may have been the intended target, due to a long-running feud between two Brooklyn housing projects.

“I’m heartbroken. I’m devastated,” Kaori’s grandmother, Linda Oyinkoinyan, told The Post. “No words could explain how I feel about this. No one should lose their life to gun violence, no matter how old they are – young, old, whatever. It’s not acceptable, it’s not good.

“I don’t want to live here anymore,” she said. “Even though it didn’t happen here, my daughter, the baby’s room, stuff, we just bought new stuff. I am tired. I’ve been through a lot of trauma in my life, too, so much. I don’t want to deal with it anymore.”

The violence unfolded around 1:20 p.m. Wednesday, when the baby’s mom, Lianna Charles-Moore, 20, was walking with her two kids in a double stroller near Humboldt and Moore streets in Williamsburg, the shots rang out, police and sources said.

She dashed into a nearby bodega for shelter when she looked down and saw little Kaori covered in blood, and began hysterically screaming, with the horrifying scene caught on store security video.

The baby was rushed to Woodhall Hospital, where she was pronounced dead at 1:46 p.m.

“We thought it was fireworks, but my son jumped out of the stroller, and I picked him up and carried him,” Charles-Moore told The Post on Wednesday.

“I was hugging him, and then when I looked to my left, my daughter was just there, lying there. She was shot in the head. She was just bleeding. It was just too much.”

According to sources, the same bullet that killed the baby then grazed her brother’s back.

Surveillance cameras at the scene released by police captured the suspects at the scene, with the passenger firing from the back of a moped while his accomplice speeds away.

NYPD Commissioner Jessica Tisch said at a press briefing on Wednesday that the pair crashed head-on into a car two blocks away, sending Greene to the hospital, where he was allegedly identified as a person of interest and taken into custody.

He is being held for questioning on an unrelated alleged domestic violence incident.

The driver of the moped is now the subject of “a massive NYPD manhunt,” Tisch told reporters.

Kaori’s family said the tot had just learned to say “mama.”

Tisch said Kaori and her mom were on a crowded sidewalk with several adults and children, including in another stroller, when the suspect fired at least two shots.

She said the shooting was gang-related, but did not provide details.

Cops do not believe the baby was the intended target, law enforcement sources said.

“I’m not gonna lie, I’ve been going crazy since last night,” Mia Torres, a neighbor who knows the family, said Thursday. “Like, I can’t stop posting the baby on my social media. I came to light all the candles. 

“I don’t know,” she said. “This is hard.”