Can Road make the house a pocket dimension, like she did in that initial fight with Allen and doll!Lenalee? Then Conrad and Lavi may slip under the radar until they flee in abject terror. XD When they leave I'd be okay with ONE person from the force coming to check on them...
Not sure that Road has the power to do that or that putting them in another dimension wouldn't trigger the no-lifesign alert, however. D: