Working for The Newcastle Herald, McCarthy wrote more than 1,000 articles on Catholic Church child sex abuse cases in the Hunter region.
Following a brief period of working as a nurse at the Royal Prince Alfred Hospital, she began her journalism career with a cadetship at the Gosford Star in 1980 before moving to the Central Coast Express Advocate.
Working alone but backed by editors Roger Brock and Chad Watson, McCarthy embarked on one of the longest running investigations any Australian newspaper has ever seen.
[5] In 2005, The Newcastle Herald assigned McCarthy to cover the sentencing of Father James Fletcher who had been convicted on multiple counts of sexual abuse against an altar boy named Daniel Feenan.
[9] Her investigation led her to Monsignor Patrick Cotter who, it was alleged, concealed the child sexual abuse of Father Vincent Ryan for decades.
McCarthy discovered church files and letters which showed that Cotter had known about Ryan's offending and did nothing to protect the children in his care.
[citation needed] A police interview conducted by Constable Troy Grant ended with a recommendation that Monsignor Cotter be charged.
"[14] As the McCarthy and the Herald chipped away, the work of Strike Force Georgina, launched in 2007 by Lake Macquarie police to pursue allegations of child sexual abuse perpetrated by Catholic priests, was also gaining traction.
[20][21] McCarthy knew Pirona had been a victim of Father John Sidney Denham, the child abuser from the St Pius X School in Adamstown.
[22][23] Pirona's body was discovered 8 August 2012 and during his funeral, his father Lou reiterated the families' support for a Royal Commission.
[24] The headline on the front page of The Newcastle Herald read "Too Much Pain", words Pirona had written in his suicide note.
In September 2012, Greens MP David Shoebridge, who had the portfolio of Justice, Attorney-General and Police, convened a public forum at the Newcastle Workers Club to discuss the need for a royal commission.
[25] Fox would later go on national television and tell Lateline host Tony Jones that he had been told to stop investigating complaints of sexual abuse against Catholic priests, including McAlinden.
[26] On 9 September 2012, the New South Wales Premier, Barry O'Farrell, announced that there would be a Special Commission of Inquiry into Fox's allegations conducted by Deputy Crown Prosecutor Margaret Cunneen SC.
[27] On 11 November 2012, Australian prime minister Julia Gillard announced a royal commission into the responses of institutions to child sexual abuse.
[28] McCarthy wrote Gillard a personal letter, sharing an email she had received from an aunt of John Pirona which said that "You'll never know the significance of what you've done but if you do nothing else, you've done that.
"[citation needed] Acknowledgement for McCarthy's and The Newcastle Herald's role in bringing about the royal commission would come from Gillard herself a year later.
[36][37] In 2015, McCarthy received an honorary doctorate from the University of Newcastle for her work exposing child sexual abuse in the region.