Special Magistrate Maria Doogan – whose Polish parents had been made to work as forced labourers for the Nazi regime – told Hayden Maxwell Green, 24, that he may be too young to realise the true evil of that period in history.

But she said the Hitler Youth knife and Nazi artefacts still held significance for many in the community.

Green, of Conder, pleaded guilty and was sentenced in the ACT Magistrates Court on Friday on a charge of possessing a knife in a public place without a reasonable excuse.

Court documents said a police search of Green in April uncovered the 30 centimetre knife in his pocket.

A picture of the black-handled weapon – featuring a swastika and "Blut and Ehre!" engraved on the blade – was tendered in court.

In a taped record of interview, Green told police he had received a call to go to a Banks home because "s--- was going wild!" and a woman had been injured.

Police found Green and two other men near the Banks home after receiving reports of people with bats and a stun gun.

Green told the court he had grabbed the knife out of "instinct" because of "paranoia", but had no intention of using it.

Green said the Nazi symbolism the knife represented held no meaning for him.

Prosecutor Paul Sweeney said Nazi paraphernalia may not be illegal, but was despicable and should be left in the past.

A friend of Green spoke of the offender's good character and hardships after a difficult youth.

In handing down sentence, Ms Doogan also warned Green that carrying a weapon provided a temptation to use it, which would increase the severity of a confrontation.

"It can be turned on you. It's dangerous for you," Ms Doogan said.

"For your own welfare, don't go around armed."

Ms Doogan fined Green and ordered he be of good behaviour for one year.