Previously he worked as an investigative television journalist with the Irish state broadcaster, RTE. One of his documentaries – into a mother falsely accused of murdering her baby – led to a book, Lost Innocence: The Inside Story of the Kerry Babies Mystery. There was a Tribunal of Enquiry at which he gave evidence.

“Barry O’Halloran’s book … is the most objective and dispassionate of the several volumes already published on the Kerry Babies. His journalistic skill is the most evident attribute of his book … the calm prose with which he describes the Tribunal hearings, and the calmness with which he offers his own version of the events … is in strong contrast to the very subjective accounts given elsewhere.”

Mary Leland, The Irish Times.

“Barry O’Halloran has written an important book on the Athenian naval economy that deserves the attention of ancient historians.  ‘O’Halloran is equally comfortable navigating macroeconomic terminology as he is Thucydides’ text.  … [the] book is, and will remain, an indispensable resource and reference for anyone interested in Athenian naval or economic history. Overall, O’Halloran’s book is compellingly argued, nicely articulated, and well researched” 

Tim Sorg, Classics Department, Stanford University, CA. Bryn Mawr Classical Review, September, 2019.

“Barry O’Halloran … has given a clear, concise, and very plausible explanation as to how the pandemic came about. His great achievement, however, is that he has done this in such a short time, that it is based on thorough research and, perhaps most of all, that it is so well-written. The first part reads almost like a thriller, with twists and turns in the story and plenty of goodies and baddies.”

Dublin Review of Books. Tom Inglis, Professor Emeritus of Sociology, University College Dublin.