By Andrea Grymes

NEW YORK (CBSNewYork) — Police are investigating a deadly stabbing at an apartment in Queens.

The NYPD said officers took a man into custody at the scene, and he is currently undergoing a psychiatric evaluation.

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At around 6:30 a.m. Thursday, police received a 911 call for an emotionally disturbed person at an apartment building in Queens Village.

They discovered a 72-year-old man dead on the floor of a bathroom. He is believed to be the suspect’s father.

Chopper 2 was over the scene as police swarmed the building on Hempstead Avenue at 222nd Street. Inside, three other members of the family were found unconscious.

Friend Ian Ramsey told CBS2’s Andrea Grymes he’s known them for years.

“It’s so sad. I mean, when I got the call this morning, it was devastating. I mean, I couldn’t think about the reality being played out. I couldn’t believe it,” Ramsey said.

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Police said they responded to a call for an emotionally disturbed person. Sources said he was naked and bloody.

“Upon arrival, the officers observed a male in the hallway acting very incoherently. He made statements that he had injured somebody inside of the apartment,” NYPD Asst. Chief Joseph Kenny said.

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When officers went inside, they found that man’s father on the bathroom floor.

They said he appeared to have been stabbed multiple times, and died at the scene. He has been identified as 72-year-old Loandows Walker.

Meanwhile, investigators said the man’s 70-year-old mother, 31-year-old brother and 29-year-old sister-in-law were all unconscious on a mattress in the living room. They were rushed to a hospital. They had no visible injuries, but sources believe they ingested an unknown liquid found in water bottles nearby.

“The apartment where this incident took place does not have any prior history of domestic violence or any other calls involving emotionally disturbed people,” Kenny said.

Those who know the family wondered how the incident could have happened.

“Very nice people. I know the wife and two sons. For the years I’ve been here, go to church every weekend. Every weekend they go to church,” Ramsey said.

Police said they are trying to figure out a motive for the incident. Police sources suspect the son may have threatened to injure the father, unless the others drank that unknown liquid, but then he allegedly went after the father anyway.

So far, no charges have been filed.

CBS2’s Andrea Grymes contributed to this report

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