A Forrest man thwarted the territory's drug testing regime by abstaining before analysis, a court has heard.
James Anthony Eimerl, 23, admitted to using methylamphetamine to ACT Corrective Services staff while on parole, but managed to return clean results when tested.
When asked how, he replied: "timing".
The ACT Supreme Court heard the evidence during a sentence hearing on Thursday.
Eimerl has pleaded guilty to forcible confinement, property damage, and theft after taking his mother hostage for almost two hours in July last year.
Court documents said had accused his mother of trying to "snitch" on him after she sought help believing he had returned to drug use.
Eimerl destroyed property at their Forrest home about 12.30pm, and demanded she stand in a doorway, threatening she would "get smashed" if she moved.
He then took her mobile phone and made a number of calls.
Eimerl continue to threaten his mother until he fled when police arrived about 2.10pm.
The court heard Eimerl had been on parole at the time of the offences.
Defence lawyer, Richard Davies, said his client returned to ice use and had been in the clutches of a serious addiction at the time of committing the offence.
But Justice John Burns commented that the offender had been no novice drug user.
The judge said Eimerl knew that if he used he would become addicted and then commit crime.
A presentence report author told the court Eimerl displayed immaturity and his capacity to self-reflect and take responsibility had been absent to a disturbing degree.
The author said the offender admitted to rorting drug tests by timing his use so his returned clean results.
Prosecutor Anna Jamieson-Williams said the offences had been Eimerl's first of family violence, but he had a history of violence or dishonesty.
Ms Jamieson-Williams said the three offences were part of one course of conduct that fell at the mid-range of seriousness.
Justice Burns will hand down his sentence next week.