Samuel Barnes, now 19, appeared in Newcastle District Court on Thursday, where he was committed for sentence after pleading guilty to two counts of armed robbery.

Two counts of attempted armed robbery and a shoplifting charge will be taken into account when he is sentenced in June.

Barnes made an unsuccessful attempt to hold-up the United service station at Muswellbrook about 10.15pm on June 6, court document state.

At about 8.35pm the next night, Barnes went to the Coles Express service station at Raymond Terrace with another male, but the pair were not allowed into the store due to their suspicious behaviour.

At 9.20pm that same night, Barnes approached the front door of the Coles Express service station at Heatherbrae. 

This time the console operator let him in. 

He pulled the hood of his jumper over his head, ran to the front counter, pulled out a syringe filled with a red liquid and demanded cash. 

He was handed $186 and fled the store with a co-accused, who had been standing in the doorway to stop it from locking Barnes inside. 

Then, about an hour later, Barnes walked into the United service station at South Maitland, produced the syringe and told the console operator “give me all the money”. 

He made off with $250 and three packets of tobacco. 

Police released CCTV stills from the robberies to the media and Barnes was identified and arrested. 

He admitted to his role in the robberies, but said a co-accused had “threatened” him into smoking ice and used a knife to make him commit the offences.

The 19-year-old said he didn’t receive any of the proceeds from the hold-ups.  

Barnes, who served about a week in custody before he was granted conditional bail, remains at liberty.