Some evidence is far less obvious than a gun.
At a crime scene, tiny items such as rug fibers, hair, cigarette ashes, or matches, and even DNA samples may become important evidence in your defense. Therefore, if you are at the scene of a crime before the police arrive, leave everything undisturbed. Do not vacuum, move items, or touch anything. Once evidence gets misplaced or damaged, a crucial link in winning your case may be lost. In addition, the judge or jury might view tampering with the evidence as an indication of your guilt.