http://www.legislation.gov.uk/ukpga/1973/36/schedule/2/paragraph/6/1998-11-19Northern Ireland Constitution Act 1973An Act to make new provision for the government of Northern Ireland.texttext/xmlenStatute Law Database2017-10-151998-11-19 SCHEDULESSCHEDULE 2 Excepted Matters6Treason and treason felony but not powers of arrest or criminal procedure in respect thereof.