My idiotic 19 year old son was arrested mid September 2019 for driving having smoked cannabis. He was cautioned for possession and given a written note about possession but told he would hear from them if he was to be charged for drug driving once toxicology results were back. He has heard nothing at all since and it's now 6.5 months since the offence. Is this normal and should he have heard something by now? If he is still likely to get a summons, how long could this go on for? Many thanks.