DOI investigating NYCHA orgies after dropping the ball in May

According to published reports DOI referred this case back to NYCHA for further investigation earlier this summer.
  Why?  Why didn't DOI take up the investigation then?  DOI is supposed to investigate fraud and corruption.  This seems to be part of the overall scandal that needs to be answered. 

NY Post reports the city Department of Investigation is finally looking into allegations of NYCHA workers’ on-the-clock orgies after first ceding a probe to the embattled housing agency.

“DOI is opening an investigation into possible employee misconduct in the New York City Housing Authority’s Throggs Neck development after further reviewing the allegations, including two complaints it received this summer about improper behavior by staff at the Throggs Neck development,” said DOI Commissioner Mark Peters.

Workers at the Bronx public-housing development allegedly put in for overtime — while putting out for one another — in wild sex parties inside a groundskeeper building and even empty apartments.

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