As a mil working dog handler it says in DA190-12 that it is the working dog reg I qoute ( I learned this one from Lou Castle) "Prior to searching a building the handler will determine wether to make the search with the dog on or off leash. Some of the factors which must be considered include: The time of day, Evidence of forced entry, the type and size of the building or area to be searched, the danger to any innocent persons in the area, the dogs ability to work off leash." It also says "THe searching team will be followed by at least one other MP to protect the search team." I think the reasons for the on leash search is cause ,I know I do, I tend to find more kids then anything. So the best thing I can tell you is use your judgement. I hope this may clear some reasons for the on leash. I dont know about your dog but if tell him to find him and your were he can get to you he will bite I dont care if your passive. It depends if your dog is trained to search and locate or just to apprehend the subject. I think if you give the command the dog should bite unless you tell him not too. Also if you lose sight of your dog what are you trained to do?