The nanny had been wrongly accused of murdering one-year-old baby girl Rehma Sabir, who was in her care in the months before her death.
In an exclusive interview with BostonHerald.com right before she left the US, the Irish woman told reporter Peter Gelzinis she was overwhelmed some 24 hours after prosecutors formally admitted they could not prove Aisling killed Rehma.
Throughout her time in prison, Aisling has steadfastly denied any involvement in Rehma's death.
"It has been crazy and hectic,” McCarthy told BostonHerald.com
“Suddenly, everything is happening so fast after going so … so very slow for almost three years. I can’t wait to get home and start my life over again. My worst nightmare is finally over.”
“What the Middlesex prosecutors did to me was scandalous,” she said, quite literally crying out her words.
“They should be ashamed of themselves. The police and (Dr.) Alice Newton, they just decided right away that I had killed the child. That couldn’t be further from the truth. I loved her and cared for her, 10 hours a day, five days a week. I would take her everywhere on day trips,” McCarthy said.
“They were wrong.
"But it seemed that except for my family and my lawyers, Melinda (Thompson) and David Meier, God bless them, no one would listen.”
Ms Brady McCarthy gave the interview last night before she boarded a flight bound for Shannon Airport.
Her flight landed this morning at 6.15am.
A tearful Ms Brady McCarthy was escorted through the airport by staff and was accompanied by her sister.
She did not make any comment to waiting reporters.