sentence — doing acts in preparation for or planning a terrorist act offence contrary to s 101.6(1) of Commonwealth Criminal Code — separate foreign incursion offence contrary to s 119.4(1) of Commonwealth Criminal Code taken into account under s 16BA(1) — objective seriousness — nature and circumstances of offence — s 16A(2)(a) — scale of intended attack relevant to seriousness — offender hoped to kill in order of 50 people — seriousness not necessarily reduced where planning not at advanced stage — planning advanced in sense that offender fully committed — as individual terrorist offender did not depend on others to commit or coordinate attack — most important aspect of readiness was offender’s determination — aimed complete overthrow Australia’s system of law and government — advancement of plans under secrecy required dedication and discipline — no explanation or qualification of objective circumstances offered which could mitigate seriousness — antecedents —s 16A(2)(m) — youth relevant to determining moral culpability — offender young and impressionable but old enough to know planning something appallingly wrong — culpability assessed as very high — rehabilitation — s 16A(2)(n) — whether offender withdrawn from beliefs motivating terrorist offence central to prospect of rehabilitation — offender’s steps towards rehabilitation cannot be judged without ascertaining where ideas came from and considering evidence that shows offender rejected those sources — need evidence offender has disavowed verses of Quran which provided motivation for religious violence — conspicuously lacking any evidence that offender has disavowed verses or is willing to consider refutation by Islamic scholars or clerics or persuasion by psychologists and counsellors — evidence given by psychologist that offender told them that ISIS allegiance renounced given little weight due to second-hand nature and non-specificity — guilty plea — s 16A(2)(g) — entered at last possible moment before jury empanelled — plea not acknowledgement of wrongdoing or expression of remorse or contrition —due to offender’s explicit contempt for Australian laws and non-Muslim Australians, acknowledgement of wrongdoing and demonstration of contrition only credible if it came from offender directly in oral evidence — plea no more than acceptance that conviction inevitable — on basis of utilitarian value alone sentencing judge allowed reduction of 12 months — specific and general deterrence — ss 16A(2)(j)–(ja) — no realistic prospect offender will abandon religiously based hatred of non-Muslim Australians and country’s democratic institutions, can only proceed upon basis that offender likely to remain danger to community upon release — specific deterrence remains strong consideration although must be doubted offender will be personally deterred — general deterrence and incapacitation strongly influential factors in determination of sentence — prevalence of offences aimed at disruption of public order and government in furtherance of Islamic ideology requires significant weight be given to general deterrence, notwithstanding offender’s youth — other offences — s 16BA — circumstances do not warrant higher penalty for primary terrorism planning offence than if that offence stood alone — when foreign incursion offence taken into account it does not indicate that any greater influence be accorded to any sentencing factor — offender warned that application may be made for continuing detention after sentence pursuant to s 105A.23 of Commonwealth Criminal Code — offender sentenced to 19 years’ imprisonment with 14 year and 3 month non-parole period