Synonyms and related words :
amassing evidence, ambling, ambulation, backpacking, close inquiry, department of investigation, detection, detective work, exhaustive study, footing, footing it, footwork, going on foot, hearing, hiking, hitchhiking, hitching, hoofing, indagation, investigation, investigative bureau, legislative investigation, lumbering, marching, pedestrianism, perambulation, perscrutation, probe, research, sauntering, sifting, sleuthing, staggering, strolling, thumbing, thumbing a ride, toddling, tottering, tramping, treading, trudging, waddling, walking, witch-hunt