In a sensational development The Middlesex District Attorney’s office announced today they have dropped the murder case against Aisling Brady McCarthy -- called the "Irish Nanny" who was charged with battering a Cambridge baby causing the child's death.

"Based on an assessment of the present state of the evidence, including the amended ruling from the Medical Examiner who performed the autopsy, the Commonwealth cannot meet its burden of proof,” said Middlesex District Attorney Marian Ryan.

McCarthy's lawyers told the Boston Herald today that the State Medical Examine changed its finding of the manner of death of the child from homicide to "undetermined."

READ MORE: Something really rotten in murder case against Boston Irish nanny

McCarthy's attorneys, Melinda Thompson and David Meier, had said they were going to move to have the case dismissed but the no prosecution decision was announced today, all but ending the case.

“Based on an assessment of the present state of the evidence, including the amended ruling from the Medical Examiner who performed the autopsy, the Commonwealth cannot meet its burden of proof,” Middlesex District Attorney Marian Ryan told the Boston Globe.

Originally, the DA's office stated 1-year-old Rehma Sabir died in 2013 from blunt-force head injuries — but also that the child had pre-existing bone fractures.

McCarthy's lawyers always contended that the infant had injuries sustained while on vacation abroad with her family, away from McCarthy's care.

READ MORE: Case against Bostin Irish nanny falling apart, say experts

McCarthy, 36, was released on $15,000 cash bail in May — and ordered to home confinement with GPS monitoring — after spending more than two years behind bars.

“Miss McCarthy was put in jail for 2½ years over a crime that never occurred,’’ Defense Attorney Melinda Thompson told reporters, noting that in order for a criminal case to be held, the medical examiner must conclude that the manner of death was a homicide.

“Not just a crime that she did not commit, but a crime that did not occur. The life of an innocent woman was ruined," she added.