"The prosecution say that the jury should have knowledge of these offences because it will assist them in determining whether or not the defendant has such a propensity to commit certainly the theft element of this offence, on the basis that he is no stranger to theft by stealing, and that his explanation that this was an innocent encounter, he was simply assisting somebody he knew, the jury need to consider against the background of his knowledge of what theft is and his participation in theft, and his observation of somebody (certainly the first incident which has been described by other witnesses) where the assailant was Male 1 on Mr Raza."
"26. In our view the judge was wrong to hold, in effect, that a propensity to obtain other people's property by one means or another made it more likely that these appellants would have committed this offence. In fact he never said that in terms, but that was the implied basis of his decision. The whole thrust of the guidance in Hanson is that the court should only admit convictions which have some probative force by reason of their similarity to the offence charged. To allow the Crown to prove a propensity to obtain other people's property by some means or another is, in our view, to allow them to cast far too wide a net. Such evidence has limited probative value and has a potentially prejudicial and harmful effect. In Hanson the court said that the judge should look for similarities between what the defendant had done in the past and what he was now charged with. Those similarities did not have to be striking in the way that similar fact evidence has to be, but there must be a degree of similarity. The fact that the convictions are for offences of the same description or category does not automatically mean that they should be admitted. It is not possible to define the degree of similarity which must be shown. That must be for the judge's discretion and judgment to be exercised on the facts and circumstances of the individual case. But the judge must strike a balance and in doing so must remember the words of section 101(3) to which we have already referred. 27. Here the judge appears to have understood section 103(2) to give him complete freedom to admit all convictions of the same category as the offence of robbery regardless of their probative effect. Robbery being a theft offence, all convictions for other theft offences could go in to prove a general propensity to acquire other people's property by one means or another. The judge did not consider whether evidence of those convictions would make it more likely that each appellant had committed this offence. It seems to us that, had he done so, he would have concluded that such evidence had little probative force. There are a great many people who have a propensity to acquire other people's property by one means or another. On the other hand, previous convictions for robbery would be much more probative and a conviction for robbing somebody using a knife to reinforce a threat of violence would increase the probative effect. In short, the more similar the circumstances of the past offences to the present allegation, the greater the probative force."