For local coverage of the case, see CNN affiliate WHDH.
(CNN) -- A 2-year-old boy and his mother have been found dead inside a Massachusetts trash bin, leaving authorities Monday to track down whomever killed the two and put them there.
Police discovered Maria Avelina Palaguachi-Cela, 25, and her toddler son Brian Palaguachi dead in the large metal bin Sunday night in the city of Brockton, about 25 miles south of Boston. Plymouth County District Attorney Tim Cruz did not identify any suspects in the pair's killings Monday, though he did say their deaths are not a "random act."
"We do not believe (there) is a general threat to public safety and the community," Cruz told reporters. "However, this investigation is focusing on an individual who has murdered a mother and her young child."
The investigation began Sunday around 9:30 p.m. when Brockton police got an anonymous call about a body inside a bin behind the building where Palaguachi-Cela lived.
The woman's body was found first, and the boy's body was found sometime later. Authorities told the public the boy was dead only after getting confirmation from the state medical examiner's office Monday, according to the district attorney. He said it was his understanding that both bodies "are fully intact."
"We wanted to make sure that we had all the information that was necessary prior to making sure that we had another body," Cruz said, explaining the delay in announcing that the toddler, too, was found dead.
Brian was Palaguachi-Cela's only child living in the United States, according to the district attorney, who added that "she does have another child in another country." He did not say where that other child was, where Palaguachi-Cela was from originally, or if immigration authorities are involved in the investigation.
The mother was last seen Thursday at her home, Cruz said. Others lived at her residence, though authorities have not revealed who else lived there, and the initial investigation is focusing on relatives and friends of the victims.
A neighbor of the victims, Denise Agnello, told CNN affiliate WHDH that the killings -- and the fact the bodies had been disposed of in a Dumpster -- were shocking.
"I was horrified because I've lived here for 11 years, and nothing like this has ever happened," Agnello said. "That's horrendous."
Their bodies Monday were sent to the state medical examiner in Boston, who will determine the cause and manner of their deaths. The trash bin has also been moved from the scene so it can be more thoroughly examined.
While no one is yet in custody, the district attorney described the investigation as "very active." The gruesome nature of the discovery, he said, added a special urgency and sense of determination.
"Who would do that to a 2-year-old child?" Cruz said.