A teenager who helped steal $200,000 worth of jewellery during armed robberies in Melbourne has avoided jail, with a County Court judge attributing his "violent and lawless" behaviour to his use of the drug ice.

Key points: Akon Mawien, 19, and Maker Mayoum, 18, were promised cash and 'girls' for stolen goods

Akon Mawien, 19, and Maker Mayoum, 18, were promised cash and 'girls' for stolen goods Mawien was given a two-year community corrections order

Mawien was given a two-year community corrections order Mayoum was given a four-year jail sentence with a two-year non-parole period

However, his 18-year-old co-offender was sentenced to four years' prison for his role in the crimes, which were carried out after another 19-year-old promised the pair cash, hotel rooms and "girls" in exchange for the stolen jewellery.

Akon Mawien, 19, smoked the drug for the second time ever on the day he agreed to rob two jewellery stores with a friend from his cricket club, 18-year-old Maker Mayoum, in July 2016.

They used hammers to smash through the front door of a watch repair shop in Russell Street in Melbourne's CBD, terrorising those inside the store who hid in a room at the rear.

The teenagers smashed display cabinets and fled to a waiting getaway car with thousands of dollars' worth of watches.

An hour later, Mawien and Mayoum smashed up a jewellery store on Sydney Road in the northern suburb of Coburg, again stuffing stolen jewellery into bags.

But members of the public were able to apprehend them as they tried to flee, and the pair was arrested by police.

In sentencing, Judge Liz Gaynor described the crimes as extremely serious and involving appalling violence.

The court heard the owner of the Coburg jewellery store was a refugee from Syria who had suffered months of nightmares and panic attacks.

"I came to Australia to escape the violence that plagued the streets of Aleppo and to give my family a safer life, but now I'm constantly on edge," the victim previously told the court.

"The loud destruction of the thick glass door almost made my heart stop out of fear, as it reminded me of the sound of bullets that I used to fear might strike my family when we lived in Aleppo."

Judge Gaynor said the shocking offending by Mawien was entirely out of character and could be explained by his use of the drug ice.

"I am satisfied it explains this dramatic and terrible change in a person who was normally … a quiet, kind, respectful and rather humble young man," she told the court.

'Excellent character' keeps Mawien out of prison

Prosecutors had urged the court to sentence Mawien to a stint in adult jail or a youth justice centre for his part in crimes which they said have become worryingly prevalent.

But Judge Gaynor said Mawien's excellent performance on bail, young age and otherwise excellent character warranted a deferred sentence.

"Had you been older, had your behaviour before and after this offending been any less impressive, had the expert assessments and references from respected members of the community been any less supportive, I would not have hesitated to adopt the prosecution submission," she said.

"The courts are always anxious to promote and support proved and demonstrated reform in an offender, particularly when that offender is young.

"This is not based on concern necessarily for that particularly offender … but more based on the premise that reformation is the best protection in the long term for the community at large."

Mayoum jailed for 'pushing it too far'

Mawien will be allowed to live in the community with strict bail conditions for 12 months, before serving a two-year community corrections order which will include community service.

The court heard he had taken full responsibility for the crimes and expressed genuine concern for the victims.

However, Mayoum was sentenced to four years' jail in an adult prison for his part in the armed robberies, with a two-year non-parole period.

The court heard he was a habitual ice user at the time and his prospects of rehabilitation were uncertain.

Judge Gaynor said she did not like sentencing someone of Mayoum's age to adult jail, but he had "pushed it too far".

"You've got a good family waiting for you when you get out. You'd better do your best to make sure you do what you can in prison to make sure this never happens again," she told him.