One may still be charged with obstruction of justice if there is a definite attempt to make unavailable evidence needed for a case, even if the unavailability is temporary until a suitable mirror can be found. It's such a broad definition for a criminal charge to have, and in this case I really think they would consider it.
Don't be silly. If a murderer burns the clothes in which he perpetrated the murder, he's not 'destroying evidence' in addition to being a murderer. Something must first have been determined to be evidence, before destroying becomes a criminal act. Neither are you obstructing justice by hiding evidence.
Actually, I believe that is the case, although the charge pales in comparison to murder. IANAL, but the Green River Killer was convicted of contaminating a crime scene because he left false evidence to throw off investigators. From that, it appears that intentionally tampering with evidence of a crime - even if you created it - is illegal.
