Just a quick point...If you're the respondents, and as you say you're arguing against his conviction...wouldn't you want to say blood isn't property and thus couldn't be stolen? It might be a typo in the question or it could be me! I've not looked through the other responses, but if it hasn't already been mentioned, try R v Sharpe (1857). Pull it up onLexis Nexis if you have access and follow through the succeeding cases until you get to the most recent/relevant. If you find that the current law is inconsistent with your argument, then moot that the previous cases were wrongly decided or took an incorrect turn. Should win you the research marks, if not the legal argument. How I miss mooting!