The 15-year-old, who legally cannot be identified, pleaded guilty to aggravated armed robbery in the Launceston Supreme Court on Thursday.

The boy was with a 15-year-old girl and 19-year-old man in July when they called a taxi to a house at Blackstone Heights.

After the driver’s phone was taken, the girl involved threatened him with a hammer before the boy abused him and the man threatened him with a knife.

Handing down his sentence, Justice Robert Pearce said at the time the boy “did not seem very sorry about it”.

“Perhaps you did not realise how robberies like this can have terrible effects on victims which last for a very long time,” Justice Pearce said.

“The man you robbed has suffered a lot. He was already ill, and you made things much worse.”

Justice Pearce said the victim was left “traumatised” and felt “unable to continue to be a taxi driver”.

“It must have been terrifying for him to be lured to a remote location and then threatened with a weapon,” he said. 

“Although you did not do that, you were part of the plan and you are just as responsible for it.”

While the teenager has no history of such offending, Justice Pearce said he was using cannabis, drinking alcohol and hanging around with the wrong people.

“What you did is so serious that it is something that I have thought long and hard about,” he told the teen.

“In the end I have decided not to send you to Ashley.”

Justice Pearce said he was unable to make the teenager do further community service because he had already been given 70 hours.

“I have decided … that this offence is so serious that a conviction should be recorded.

“I make a probation order for a period of 12 months… with the special conditions that you must attend educational, personal, health and other programs as directed.”

A $270 compensation order was made in favour of the driver.