A 37-year-old Brooklyn mother, Qiao Zhen Li, and her four young children, were stabbed to death in Brooklyn, N.Y. late Saturday night. According to the New York police department, a “person of interest” is in custody and the police are not looking for other suspects.

NBC News reported that Qiao Zhen Li, along with William Zhuo, 1, Amy Zhuo, 7, and Linda Zhuo, 9, and Kevin Zhuo, 5, were stabbed in Brooklyn’s Sunset Park neighborhood. William, Amy and Linda were pronounced dead at the scene while Qiao Zhen Li and Kevin were taken to local hospitals but doctors were unable to revive them, reports New York Daily News.

The stabbings occurred in an apartment and the suspect was found inside the Brooklyn residence. According to the Daily News, the suspect may be related to the children and a police source talking to the newspaper said, “It’s looking like a domestic-violence case.”

According to reports, the father, who was not home at the time, became distraught after being informed by the police of the incident, another relative was also seen being comforted by neighbors, the Daily News reported. The New York Post has a photo of the alleged attacker, a 25-year-old male believed to be the children’s cousin, covered in blood and being escorted from the scene by a police officer. A police source talking to the Post said a machete and a pair of scissors were recovered from the Brooklyn residence. The suspect was living at the residence and Qiao Zhen Li’s sister had called 911.

May Chan, a neighbor who spoke to the Daily News, said she regularly saw the four children playing in the neighborhood. Chan said, “They’re little kids ... that’s so heartbreaking. Innocent kids, my God.” The suspect has yet to be charged and is currently being questioned by the police.