"It's tragic the child was tossed in the trash Dumpster like that," said St. Louis police Capt. Michael Sack. "It's unconscionable that anybody would do that."

Police made no arrests Wednesday and said the investigation was ongoing.

Wayne Ross, 32, of St. Louis, was among relatives who gathered outside the apartment building. He said his sister Melissa Jackson, 28, is Marquell's mother.

Ross said that his nephew was Jackson's only child and that she is pregnant. He described Marquell "a very happy baby" who "loved to smile and play."

Ross said he wants answers to what happened to his nephew. He said he only saw his sister as officers led her off to police headquarters for questioning. He said the boy's father lived elsewhere.

Another relative of Jackson's declined to comment; others could not be reached Wednesday.

Frank Elliott, who owns the four-family flat, said Marquell lived there with only his mother. He said they moved there in September, and he called them nice people.

"It's shocking," Elliott said. "I just can't even imagine."