Hero bystanders perform a citizen's arrest on a coward, 22, who mugged a 91-year-old pensioner after bingeing on Xanax and losing 'all his money' on the pokies

Security guards have chased down a 22-year-old coward who robbed a 91-year-old woman that was walking to her car after grocery shopping.

The dramatic citizen's arrest was captured on body cam footage and shows how the brave responders managed to bring him down. 

Jourdan Kidd-Karam pleaded guilty to the $65 theft at the Runaway Bay Shopping Centre on the Gold Coast at the Southport Magistrates Court on Tuesday.

The man's lawyer argued he'd been bingeing on the prescription drug Xanax and just lost 'all of his money' playing the pokies. 

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Jourdan Kidd-Karam was brought down by security guards after robbing a 91-year-old woman

The court heard that Kidd-Karam had taken at least nine Xanax tablets and drunk up to three beers early that day, leaving him with memory of the incident

The court heard the pensioner was walking to her car at about 6.15pm on February 3, when Kidd-Karam reached into her shopping trolley and snatched her purse.

Kidd-Karam then sprinted across the car park to make his getaway.

But a nearby security guard patrolling the area gave chase, eventually running down the thief and tackling him to the ground.

Another security member, along with a van driver, soon followed and the group made a citizen's arrest. 

The court heard that Kidd-Karam had taken at least nine Xanax tablets and drunk up to three beers early that day, leaving him with memory of the incident.

'He'd lost money gambling and was in a position where he was under the influence of a drug,' prosecutor Joel Sleep told the court. 

Kidd-Karam was sentence to 80 hours of community service and 12 months probation 

Defence solicitor Christopher Hannay told Seven News Kidd-Karam's congnitive function has been greatly diminished due to his violent upbringing as a child.  

'He's totally dysfunctional,' Hannay told the court.

'There's been abuse, there's been drugs.

'He's had no father figure.'

Magistrate Grace Kahlert told Kidd-Karam: 'You should rightly be ashamed of your behaviour.'

He sentenced Kidd-Karam to 80 hours of community service and 12 months probation, labeling the crime an 'opportunistic' theft'.

Magistrate Grace Kahlert told Kidd-Karam (pictured outside court): 'You should rightly be ashamed of your behaviour'