A Mitcham mum says anyone caught with a knife should be locked up straight away after her disabled son was nearly mugged.

Tracy Wilson was on her way home on January 31 when she got a call just after 10pm from her 28-year-old son - who has learning difficulties, depression, anxiety and autism - saying he was nearly mugged at knife-point.

"He was going down Belgrave Walk footpath and two guys walked right up behind him," she told the Wimbledon Times.

"They wanted his phone. They walked in front of him and blocked off the footpath and one of them pulled out a knife."

The 28-year-old refused and threatened to dial 999.

This seemed to do the trick as the two men then fled the scene.

But ever since that traumatic experience, Tracy says he has had trouble sleeping.

"He can't get that image out of his head," she added.

"It will affect him more than others because of his disabilities.

"Now he feels like he has to go out with protection."

Tracy wants to see anyone caught with a knife put straight into prison.

"You should get locked up right away, it's the only way to deal with knife crime." she continued.

"I’m afraid to go out in the dark. It's getting worse and worse living around here.

"People work hard for what they get and then these people try and just take it away from you."

While nothing like this has happened to her family before, she says people around the area are living in fear.

"People are so afraid," Tracy said.

"Random stop and searches need to be brought back. We need more police, more CCTV.

"But anyone caught with a knife should be locked up, no ifs or buts."

About 30 minutes after the attempted mugging, police arrested two men close to where the attack happened.

The Met have been contacted for an update on the case.