Q Timeline of the taping scandal
June 2013: Garda Ombudsman report on arrest and beating of Anthony Holness in Waterford refers to recording of phone conversations in garda station. The report goes unnoticed.
October: Garda management becomes aware of the extent of the phone recordings due to another case.
November 11: Garda Commissioner consults with Attorney General's (AG) office on recording of phone calls.
November 25: Ian Bailey, the self-confessed suspect in the Sophie Toscan du Plantier murder, and his partner Jules Thomas, are separately suing the State for wrongful arrest in the investigation.
Their legal teams are told "unexpected electronic material" has been found in a trawl of garda case files. The High Court gives the gardai until this week to unscramble the data – believed to be recorded phone calls.
November 27: Garda Commissioner orders a halt to routine recording of non-999 calls at Garda stations.
February 28, 2014: Department of Justice informed by Chief State Solicitor's Office and gardai about the recording of phone calls.
March 10: Garda Commissioner writes to the Department of Justice revealing gardai were involved in widespread recording of phone calls in and out of stations.
March 11: Commissioner Callinan meets with officials in the Department of Justice and the AG's office on the issue of the taped phone calls related to a civil case.
March 15: Mr Shatter flies to Mexico for St Patrick's Day visits.
March 19 and 20: Garda HQ sends copies of letters between it and the AG's office and the Data Protection Commissioner on the controversial taping of phone calls to the Department of Justice.
March 21: Mr Shatter returns from Mexico.
March 23: Taoiseach Enda Kenny meets AG Maire Whelan, who briefs him on taping scandal.
March 24: Mr Shatter learns of the issue and meets Taoiseach and AG.
On Taoiseach's instructions, Dept of Justice Secretary General Brian Purcell meets Commissioner Callinan to inform him of Government's views.
March 25: Cabinet meeting due to be dominated by Transport Minister Leo Varadkar's demand for Commissioner Callinan to withdraw comments about whistleblowers.
Mr Callinan informs Department of Justice of his retirement at 9am. Cabinet meets at 10.30pm and Mr Shatter receives the letter sent to him on March 10 at 12.40pm.
Government decides to launch Commission of Investigation into garda taping scandal.