The ACT Supreme Court has heard Lloyd Edwin Burch, 20, drank two litres of beer with friends in Phillip in October last year, before entering the Ali Baba store armed with a knife.

He produced the knife, threatened violence against staff, and demanded money.

The young man then left the store, but was tackled by members of the public who had witnessed the aggravated robbery.

He was arrested and brought before the courts, pleading guilty to the serious offence eight weeks later.

Mr Burch is the son of Ms Burch, whose portfolios include education and training, disability, children and young people, and women.

Ms Burch was in court on Wednesday to support her son as he faced sentencing before Justice John Burns.

His defence barrister Alyn Doig conceded the offence was ‘‘very serious’’, and said it was ‘‘very, very lucky’’ no one had been hurt when by-standers intervened.

But Mr Doig argued the court should suspend the sentence, pointing to Mr Burch’s young age, his efforts to rehabilitate, his early plea, and the lack of pre-meditation and actual violence in the crime.

He said Lloyd Burch clearly had issues with drugs and alcohol and had seen the robbery as a means to get ‘‘easy money’’.

But he said Lloyd Burch was addressing his drug and alcohol problems, and also planned to study at Canberra Institute of Technology and through a pre-admission university course.

Mr Doig told the court the offence had helped to crystallise in his client’s mind the fact that he needed to focus on his future, something that had given his parents hope.

‘‘There has been a marked change from late last year to today, one that gives them some hope for the future,’’ Mr Doig said.

The barrister pointed out recent tattoos his client had inked on his hands, which read ‘‘faith and ‘‘hope ’’. He said those tattoos were there as reminders as he tried to change his future.

Lloyd Burch had also written a letter of apology to the victims, something he did of his own free will.

‘‘It’s his letter, it’s not one written for him and he’s simply penned his name to. It is his letter,’’ Mr Doig said.

Justice Burns said it was difficult to sentence the man due to the short period of time since the offence, which limited his ability to assess the offender’s commitment to rehabilitation.

He deferred sentencing for six months, and will come back and check on his progress in October.

‘‘You have to realise how close you are to the edge of going to prison full-time,’’ Justice Burns told Lloyd Burch.

‘‘Your future is now very much in your own hands.’’

Crown prosecutor Anthony Williamson said he would not resist the deferring of the sentence, but argued that if Lloyd Burch failed, he should be sentenced to a maximum of between four and five years imprisonment.

If Lloyd Burch is able to show progress, he will still face periodic detention or community service with a suspended sentence.