A caller to the police reported that a boy needed an ambulance. When the police arrived on Wednesday afternoon at the address the caller gave, an apartment in a house in Amityville, on Long Island, they found an unresponsive pajama-clad child lying on a couch. There were no adults present

By evening, the boy, Adonis Reed, 4, had been pronounced dead. And on Thursday, the Suffolk County authorities declared his death a homicide, although details about who might have killed him remained elusive.

The Associated Press reported that detectives said the boy showed signs of having been assaulted.

“We have no idea what’s going on,” Adonis’s aunt, Rosemary Shorter, 33, said as she placed candles on the stairs of the yellow house at 89 Ketcham Avenue where he was found dead.