Mobile phone records show that on the day his wife was murdered, there were 18 communications between murder accused Joe O'Reilly and the woman with whom he was having an affair, the court was told.
Det Garda Joanne O'Sullivan told prosecuting counsel Dominic McGinn BL that she created a spreadsheet showing all incoming and outgoing calls and text messages that went through Mr O'Reilly's phone on October 4th, 2004, the day his wife was found beaten to death in their home.
Det Garda O'Sullivan was giving evidence on the 12th day of the Central Criminal Court trial of Mr O'Reilly (35), of Lambay View, Baldarragh, the Naul, Co Dublin, who has pleaded not guilty to murdering Rachel O'Reilly (30), his wife and mother of their two children, at the family home on October 4th, 2004.
In total, the list shows that 18 calls or texts took place between Mr O'Reilly's phone and that of Ms Nikki Pelley, with whom he was having an affair.
The document also shows a total of eight calls or texts between Mr O'Reilly's phone and Derek Quearney, the co-worker with whom Mr O'Reilly claimed he spent the morning inspecting posters in the Broadstone bus garage in Phibsboro.
The document also shows calls made to and from family members and others that afternoon and evening after Rachel O'Reilly's body had been found.
Under cross-examination by defence counsel Mr Patrick Gageby SC, Det Garda O'Sullivan admitted she was dependent on the accuracy of other people's reports in creating the spreadsheet.
She also agreed with him that she "could not warrant on this document who was speaking to whom". Asked whether there was any call from Ms Helen Reddy and Mr O'Reilly at about 8pm on the night of the killing, she said: "No."
IT technical consultant Karim Ben Abdullah, who works as a consultant engineer for 02, then gave evidence.
He told Mr McGinn he was asked to provide a report in relation to the investigation and that when he did so, he went back to the base source of original call data records in the telephone exchange.
In particular, he said he was asked to look at the mast at Murphy's Quarry, close to the O'Reilly household.
He said the mast which picked up Mr O'Reilly's phone call pointed in a north/northeasterly direction.
When Mr McGinn asked him for his expert opinion as to whether it was possible for the Murphy's Quarry phone mast to pick up the call of a person making a call in the Broadstone bus garage, he said: "That's impossible."
Another engineer with 02, Eddie Gleeson, told Mr McGinn that the data he examined showed a call from Helen Reddy's phone to Mr O'Reilly, lasting 3 mins 14 secs on October 4th at 8.24pm.
Asked whether it was possible for the telephone mast in Murphy's Quarry to pick up a signal from a phone in the Broadstone bus garage, he said: "I would say it is extremely unlikely."
He said that the network was designed so as not to let this happen. "It would cause huge engineering problems for us," he explained. Mr Gleeson also said that on the day of the killing, calls made from Mr O'Reilly's number used the same handset with the same SIM card at all times.
The trial before Mr Justice Barry White and a jury of nine men and two women continues today.