Where a defendant is arrested for the possession of contraband that he obtained from a supplier, the defendant is not criminally accountable for the contraband possessed by the supplier if he is purchasing it for personal use. But if he is distributing it with the aid of the supplier, they share a common criminal design and he may be found accountable for the entire amount.The 1st District Appellate Court affirmed the decision of Cook County Associate Judge Dennis J. Porter.A Chicago police officer was conducting …