The alleged shooter, the girl's father, was later found dead on the street, police said, of a self-inflicted gunshot wound.
The victims were shot inside a fourth floor apartment on Sutter Avenue in Brownsville, inside the Van Dyke Houses, where the girl called 911 around 11:20 p.m. to report that her father had shot her mother and sisters.
"Body-worn camera of her calling 911 just breaks your heart," NYPD Chief of Detectives Joseph Essig said. "She is saying, 'Daddy is coming from my birthday. He didn't bring presents'...It's really heart wrenching. They have no prior domestic history, there is no 911 calls between them."
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The victims were identified as 45-year-old Rasheeda Barzey, 20-year-old Solei Spears and 16-year-old Chloe Spears. They were reported deceased at the scene.
Health + Hospitals released a statement on the death of Barzey, who was a NYC Health + Hospitals employee.
"We are deeply saddened by the senseless death of a member of the NYC Health + Hospitals family. In addition to reaching out to relatives, we have activated our Helping Healers Heal team to support those who worked beside this staff member and may need grief counseling," spokesman Chris Miller said.
It's not yet known what her position was at the hospital.
Police said they found the 9-year-old girl hiding in the closet.
"We believe that he had a 20-year relationship with the female killed," Essig said. "He comes to the apartment for the...daughter that they have in common, for her birthday party."
The 46-year-old suspect, Joseph McCrimon, was found outside a nearby building in the same city-run housing complex.
The motive is unclear at this time.
"We know he left in an agitated state to meet her," Essig said.
Even though there was no domestic history, police said McCrimon had a violent past, including a conviction 28 years ago for manslaughter. Still, authorities say they may never know much more about these murders.
Anti-violence activists tried to pull together a community still in disbelief...
"There's a lot, maybe even mental health issues, that we don't even address in the neighborhood," said Daniel Goodine, with Men Elevating Leadership.
And for one very traumatized little girl, that job seems daunting.
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"It's sad," neighbor Rashawn Morris said. "There's just too much going on in this world right now for this. To lose your whole family, it's tragedy.."
Shea said the recent spike in shootings are leaving many disillusioned.
"I think some are becoming numb to this," NYPD Commissioner Dermot Shea said. "None of us up here are numb to this. These are real people. I spent this morning watching body camera video of that terrible incident last night in Brooklyn. It would tear your heart out to see the little girl from that crime."
Two guns were recovered at the scene.
"Really troubling and tragic situation," Mayor Bill de Blasio said. "A horrible, horrible situation, and my heart goes out for those who have been lost."
The investigation is continuing.
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