His father was Frank Hanna, a Northern Ireland Labour Party MP.
[2] Hanna's practice was focused on the Dublin and South-Eastern circuits, where he specialised in personal injury cases and the law of tort.
[7] He presided over a planning law case involving Van Morrison and his wife Michelle Rocca in 2010.
This was considered to be the first Irish case involving the enforceability of online terms of service.
He applied a test of "ordinary common sense" to assess evidence in a personal injuries case involving a woman who had slipped in a car park.