 Callinan was assigned to manage Strategy and Change Manangement but was soon reassigned to Operations; as part of this appointment, he was assigned with managing all policing within the Republic of Ireland and any national security issues.Fachtna Murphy resigned as Garda Commissioner in late 2010; Martin Callinan, who by this time was an extremely well versed guard and had taken part in almost all areas of the force, was one of the top choices for the job.He was successful and appointed to the position on the 28 December 2010.