
Next month will mark the eighth anniversary of one of the most shocking crimes ever committed in Ireland.
Alan Hawe killed his wife, Clodagh Hawe, and three sons – Liam, Niall and Ryan – in Castlerahan in 2016.
A forensic detective who was involved in the case has written a book about his career, called Identity. John Sweetman writes about the Hawe case in detail.
He has been speaking to Eoghan Murphy, firstly about how he became a fingerprint and handwriting expert.