Isaac Rozs, 21, will spend at least two years behind bars after pleading guilty to robbery armed with an offensive weapon.

Court papers said Rozs was armed with a long silver kitchen knife when he held up the Metro Service Station at Prince Edward Avenue, Culburra Beach around 6.30pm on December 3, 2017.

Rozs was captured on CCTV footage entering the business and walking around the shop for a number of minutes earlier in the afternoon, before asking the female attendant what time the business closed.

CCTV footage captured Rozs, dressed in different clothes in an attempt to hide his identity, enter the business around 6.30pm, wearing a black hooded jumper, black tights, with a blue bandanna wrapped around his face and wearing white gloves.

Carrying a black backpack and a large steel kitchen knife, he approached the female attendant behind the counter demanding “cash”.

The  woman gave him a number of $5, $20 and $50 notes before he was seen running in an easterly direction towards Prince Edward Avenue.

A number of witnesses told police the offender had ran in the direction of Brighton Parade. Following investigations police went to a house in the street, found a gate to the rear of the property open, along with the back door of the home open.

Police say they found Rozs dressed in nothing but his underwear and a search of the home found a large amount of Australian currency partially hidden on a bed.

Police recovered $790 in cash and also located a number of pieces of clothing, the same as those captured on CCTV from the robbery.

Rozs told police he was intellectually impaired and resided at a care facility in Goulburn.

Court documents stated Rozs had a lengthy criminal history with 58 charges for a wide variety of offences.

In Nowra District Court Judge Warwick Hunt sentenced Rozs to three-and-a-half years in jail from January 28 this year. He set a non-parole period of two years.

Rozs will be eligible for release on January 27, 2020.

Read more: Crime Court