yes but if he is growing illegally he has limited options, if the neighbor suspects he has weed or has seen him with it. The best thing is to call the police and tell them that you need to file a noise complaint because his neighbors dog is constantly barking, you normally do this when the dog is infact barking so when the police arrive there is something to substantiate it. Also while there he deffinitely should say that his neighbor issued a verbal threat, and have him state exactly what was said. Its pretty much filing a police report. Thats the best option, or he could talk to the landlord and have him mention something if he lives in a apartment complex. If the neighbor does seem unstable and would attack your son he may only have the option of moving. Also with a filed police report if something does happen the court will look more favoribly towards your son rather then is being a his word against mine deal. especially if within the report a threat of violence is documented.