A group of teenagers brandishing a machete and extendable batons — who were attempting to steal a hooded jumper from another teen — sparked a lockdown of Westfield Marion shopping centre, Adelaide’s Youth Court has heard.

Three teenagers — a 16-year-old and two 15-year-olds — have been arrested and charged with aggravated counts of affray, assault and robbery over the incident, which led to an emergency response inside the centre about 3pm on Sunday.

During a court appearance by two of the teenagers on Monday morning, the 16-year-old’s defence lawyer Kassandra Girolamo denied that there were “knives or machetes involved” and said the “mass panic” was caused by shopping centre management, not the charged teens.

A lawyer for a 15-year-old from Morphett Vale, who appeared in court separately to his co-accused, said the teen also denied he was armed with a machete.

But, she said he accepted he was engaging in antisocial behaviour and had been in the company of other people who had batons.

Prosecutor Rory Ormerod told the Youth Court that the three accused followed another group from the nearby Oaklands railway station to the shopping centre, where the trio tried to steal a hooded jumper belonging to one of the alleged victims.

“It’s alleged that the weapons have been brandished by all three,” Mr Ormerod said.

Mr Ormerod said that, after a short chase, one of the victims removed his hoodie and placed it on the ground, where it was collected by one of the accused.

The court heard police found two expandable batons and other items of interest — including clothes the offenders were seen wearing on CCTV — at a Clovelly Park address.

The court heard the 15-year-old from Morphett Vale, was found in possession of the stolen hoodie, but police did not find a machete.

The court also heard that the 16-year-old accused had relevant prior offending, including two counts of aggravated assault with a weapon, one count of theft, one count of damaging property and disorderly behaviour.

His lawyer placed the blame for the “mass panic” not on her client but on a “rash decision” by the centre management to notify everyone that there were armed offenders on the premises.

“This has been either a miscommunication or just a mishandling of Westfield,” Ms Girolamo said.

“It was never [my client’s] intention that things escalated to the point that they did in so far as the response is concerned.”

The Morphett Vale teen’s lawyer echoed those statements, and said “it was never his intention to cause havoc or harm to any members of the public” and that the incident  transpired from a “threat” made by the other group involved.

“This has all arisen out of a conflict between two youth groups,” she said.

Ms Girolamo said it was not “unusual at shopping centres such as Westfield for there to be fights between youths or even fights between adults”.

“It’s never before resulted in a full lockdown of a shopping centre that created mass panic and injuries to members of the public,” she said. 

“[My client] instructs me that he had no idea that the shopping centre had even been put into lockdown. He had already left.”

Teenager struggling with homelessness, court told

Ms Girolamo said that “a lot of the allegations are contested” at this point in time. 

“My client denies any allegation that there’s knives or machetes involved either by himself or any of his co-accused. My client denies any allegation that he’s hit any of the other youths,” she said.

The court heard there had been allegations of a “chair being thrown, an argument has gone ahead, and then there’s been running”.

Ms Girolamo said the incident was due to “immaturity”.

“These are not adults, these are children. They’re having an argument. They’re carrying batons,” she said.

“CCTV will be the most compelling evidence that prosecution can obtain.”

The Morphett Vale 15-year-old asked to be released on bail to live with his mother.

The court heard he had previously received a suspended sentence for offending that included assault, thefts and possession of a knife.

His lawyer told the court the teen had taken “significant steps … with re-engaging with school”.

The court heard the other 15-year-old had refused legal advice.

The court was also told the 16-year-old and his mother were struggling with homelessness, and his lawyer suggested the boy could be released on home detention bail to a friend’s address.

The prosecution opposed all forms of bail for each of the defendants in the interest of protecting the community and said there was a risk of re-offending and a risk of the contamination of evidence.

Magistrate Kathryn Hodder ordered comprehensive bail remand information reports for all three defendants, who will return to the Youth Court on July 4.

The reports will consider the suitability of addresses suggested for home detention bail with full monitoring conditions, as well as the teenagers’ willingness and ability to comply with home detention bail.

Centre plunged into lockdown

Shopping centre management activated an alert and evacuation alarm, and the centre went into lockdown around 3pm.

A number of police swarmed the centre to search for the groups involved, but did not find them.

SA Police Assistant Commissioner Scott Duval said by the time the first officers arrived, the centre had put its emergency procedures in place.

He said police would review and learn from the events, including the time it took to clear the centre and evacuate people reportedly sheltering for more than two hours in retail stores.

“There was obviously an amount of inconvenience that’s caused to people but what I’d say to that is all of our actions are about ensuring public safety and nothing we’d do would ever compromise public safety,” Assistant Commissioner Duval said.

“We can’t release people while we’re still in a period of response.”

Assistant Commissioner Duval praised the community for cooperation during “difficult times”.

“I certainly empathise with those people that were caught in shops and particularly with young children, the effect of that is well acknowledged,” he said.

“But at the same time we need to make decisions that are all about people’s safety.”

Senior Constable Matt Brown told ABC Radio Adelaide people who felt impacted by the events that unfolded at the shopping centre should seek mental health support.

“Anyone who was affected by yesterday’s events, either you were at the scene when it happened or you had to go pick up a family member or friend who was working at the centre, please contact welfare services or some sort of counselling if you are feeling stressed out or anxious over what happened yesterday,” Senior Constable Brown said.

“Incidents like these we just need to gather around each other and make sure everyone’s OK, and be grateful that the incident was handled very safely.”