Green, 49, had been languishing in a psychiatric emergency room at the Kings County Hospital for nearly 24 hours when she collapsed from a blood clot.
She lay on the floor for an hour, in full view of nurses, doctors and security guards, before a nurse nudged her body with her foot, then checked her pulse. By then she was dead.
Six hospital employees lost their jobs in the incident, but the probe by the city's main investigative agency raises the possibility that some could also face criminal charges.
The report said that after Green died, a senior nurse at the hospital made three false entries in her medical records to make it appear as though she had been checking up regularly on her patient.
In actuality, the report said, Green had been ignored - a fact confirmed by security camera footage of her collapse and slow death.
The Department of Investigation said the nurse subsequently admitted in an interview that she fabricated entries in Green's progress notes because she was afraid of losing her job, but lied about the nature of the inaccuracies.
Separately, a nursing aide made entries in a hospital journal falsely indicating that she had observed Green asleep during the hour when she was actually lying face down and dying on the floor, the DOI report said. The aide later admitted, according to the report, that he wasn't checking on Green during the critical time period, and was actually on a break.
City authorities also cited factual inconsistencies in medical records filled out by several doctors at the hospital, including one whose claims to have attempted to examine Green were contradicted by the security footage.
"This is a case of omission and commission that ranged from doctors who failed to examine Ms. Green to medical personnel who falsified the hospital's records regarding her condition and treatment," DOI Commissioner Rose Gill Hearn said in a statement.
"We hope that our factual findings will ensure that the troubling events that surrounded Ms. Green's death are never repeated."
A lawyer for Green's family, Sanford Rubenstein, said her relatives also hoped the report might lead to a criminal prosecution.
"Anyone identified in that report who committed a criminal act should go to jail," he said.
A spokesman for Brooklyn District Attorney Charles Hynes said the office was reviewing the report but declined to comment further. No criminal charges have been filed so far.
The city, which owns and operates the hospital, has settled a wrongful death lawsuit with Green's family for $2 million.
The city's Health and Hospitals Corporation has also pledged additional millions of dollars to upgrade the facility, which, even before Green's death, had been the subject of lawsuits and a Justice Department investigation alleging dangerous conditions and patient neglect.
The improvements include a new $153 million psychiatric center. The hospital has also hired hundreds of employees to its medical staff.