The 69-year-old mother of four babies who were found dead in a freezer in the US city of Boston will not face criminal charges.
The bodies of the siblings – two boys and two girls – were discovered in shoe boxes wrapped in tinfoil on 17 November 2022 after a man called police.
He said his wife had found them while she was cleaning his sister’s apartment in south Boston, the Suffolk County district attorney’s office said.
District attorney Kevin Hayden called the investigation “one of the most complex, unusual and perplexing that this office has ever encountered”.
Investigators don’t know whether the four babies – thought to be 37 to 40 weeks old – were born alive, which was part of the reason not to bring criminal charges, Mr Hayden said.
Also, it was not clear exactly when or where the children were born, what happened to them and how the mother was able to conceal her pregnancies.
Investigators were able to identify the infants’ parents but found their father died in 2011 and their mother would unlikely be able to stand trial due to cognitive issues.
Post-mortems found no signs of obvious injuries to the infants who still had their umbilical cords attached.
The mother had another child with the same man but that baby was given up for adoption.
She was interviewed but the district attorney said she appeared confused and did not understand where she was, or who she was talking to and was not able to provide authorities with any relevant information.
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“A prosecutor’s office cannot ethically move forward with a case that, in good faith, it believes it cannot bring to trial,” Mr Hayden said.
He added: “This investigation, which is one of the most complex, unusual and perplexing that this office has ever encountered, is now complete.
“While we have some answers, there are many elements of this case that will likely never be answered”.
A lawyer for the woman, who lives in a residential healthcare facility, did not respond to Associated Press’s request for comment.