(ii) The reasons for which a person can be deprived of their liberty under international law • Under international law, deprivation of liberty must be: o in accordance with law; and o not arbitrary. • For detention not to be arbitrary, it must be: o for a legitimate purpose; o necessary and proportionate in pursuit of such purpose; and o non-discriminatory. (iii) The length of time for which a person can be deprived of their liberty under international law without being charged • Anyone arrested or detained for any reason, including in relation to a terrorist offence, has the right to be brought promptly (without delay) before a judicial officer to challenge the legality of their detention. • All persons arrested or detained on a criminal charge are entitled to a trial within a reasonable period. • Even where detention is lawful and not arbitrary at inception, it can become arbitrary if the length of detention is not necessary and proportional to the circumstances. There should be an opportunity for regular judicial review of the continuing necessity for detention. • It is recognised that terrorist offences are serious offences and may present particular security concerns. The investigation of these offences may also take longer because of their complexity and possible international component. All of these factors must be weighed by a judicial authority when making a decision as to the necessity to detain and the appropriate limits on the length of detention. 14