Key question: Will European court ruling impact Graham Dwyer murder conviction?

Even if the killer's conviction is preserved, it is possible EU court judgment could affect other cases involving data retention

File Pic Shows: Graham Dwyer (42) of Kerrymount Close in Foxrock in Dublin 18, has pleaded not guilty to the murder of Elaine O'Hara on 22 August 2012. Pic: Collins Courts.

There had been much anticipation of yesterday's Court of Justice of the European Union's (CJEU) hearing of the appeal by Graham Dwyer in relation to his conviction for murder in 2015.

The key question out of the CJEU’s eventual ruling, which will likely take at least three months to be delivered, is not whether or not the court will rule in Dwyer’s favour. It would be very surprising if it does not, on foot of its own decisions in previous cases.