The plan was to either capture or kill large numbers of the Victorian police. The prime targets were the Aboriginal police-trackers. The idea was to lure the police to Glenrowan. In order for this to happen they needed to show themselves with the guarantee that once they had done so, the police were sure to follow.
Ned knew that the trackers and police would come looking for him. It had been many months since he and the boys had shown themselves. It was known that Aaron had four policemen staying with him in his hut. Killing Aaron would surely have the police in hot pursuit.
Most historians believe that Aaron's execution was part of the plan, however another theory is that Aaron was only meant to be frightened and Ned was unaware that Aaron had been killed by Joe.
Either way, the 'spy' as Aaron was known, was executed, unfortunately the police were so frightened that they did not leave the hut until many hours later. It is understandable that the police should be so scared, after all they did not know how many outlaws were involved and they were prime targets inside the well-lit hut.
Joe and Dan performed this 'execution' via the bailing up of a local German market gardener named Anton Wicks. Anton often got lost and would ask Aaron to show him the way home. This time however he was being forced to ask for directions at gunpoint, "it is Anton, I have lost my vay". Aaron thought nothing odd about this and opened his rear door. Aaron peered out into the darkness and said (believing he was talking to Wicks) "Do you see that sapling over there", it was to be a joke, instead Aaron received a fatal wound. Joe fired two shots and Aaron was killed almost instantly. Aaron bled so profusely that at first it was thought he was shot in the neck. Dan then came in to the hut via the front door. He greeted both Aaron's wife and her mother, Mrs. Barry, who happened to be visiting the young couple that fateful evening. The four policemen had taken cover in the bedroom, and when Mrs. Sherritt went in to inform them that the outlaws wanted them to come out, they seized her, the object being either to protect or to use her as a shield. When Aaron's mother-in-law went in to check on her daughter, she too was detained by the policemen.
Joe and Dan fired a few shots into the little slab hut and made a small attempt to set it on fire before they left for Glenrowan.
Anton crawled all the way home, in constant fear of his life. (a fact ignored by many writers, thanks to Allison O'Sullivan, a descendent of Wicks, for that information)
Much has been made of the cowardice of the police protecting Aaron inside the hut. Considering the advantage the outlaws had in that they were in the dark, and the police were in the light, it is no wonder they stayed put. It is interesting to note however, that Joe stepped right into the room well lit by the open fire, and was not shot at by the hiding police. These police were to share in part of the Kelly...