This is not an offense that can be leveled when someone accidentally destroys evidence. This offense means that someone has changed, hidden, or destroyed concrete evidence on purpose, in order to hinder any investigation. Under federal law, this offense is punishable by up to 20 years in prison. Heavy fines could accompany this sentence as well.
Now an investigation does not even have to be underway; if someone only thinks they might be investigated and tampers evidence accordingly, then they could face this charge. This means altering evidence "in contemplation of" a search or investigation. An offense of tampering with evidence could be anything from swallowing a joint of marijuana (as seen in "Up in Smoke") to cooking the books (all too commonplace). Since there is such a wide array of activity that could bring on this charge, let's break down the components of this multi-faceted offense.
First, there is the evidence. Purposefully burning papers is not automatically an evidence tampering crime. If no investigation develops, or if those papers would never be used as evidence, then they are not evidence. Perhaps someone is afraid that they will get in trouble because it looks like they are smoking marijuana (in a state where it is illegal, of course), but they are in fact smoking a clove cigarette. If they try to flush the cigarette down the toilet, this would not be tampering with evidence. That cigarette would never become a piece of evidence in this case. Even if the person actually thought they were smoking marijuana, it would not matter that they tried to get rid of the cigarette. It's not evidence of any kind. Things would be different, however, if that person were in fact smoking a joint of marijuana.
Then there is the aspect of the offense having to be committed "knowingly". A prosecutor will have to be able to establish that the person knew that they were destroying evidence, or something that could turn into evidence in a current or potential investigation. For example, the prosecutor would have a much easier job to prove that the shredding of documents was committed knowingly by an accountant or business owner who was facing an audit or investigation. It could be an uphill battle, however, to prove that an intern or janitor who is given the same papers would have been knowingly destroying the evidence of embezzlement.
Finally, there is the matter of "intent". The destruction or altering of evidence must have been committed in an effort to stop or obstruct an investigation. Take for instance, a business owner who knows that they are looking over falsified account information, but perhaps, a clumsy move tips over their coffee cup, causing the ink to bleed and blur. That owner knows that the information would implicate them in criminal activity, but the destruction of that evidence was not intended to hide it from an investigator. Fortunate for them, maybe, but not intentional.
How can you defend against this charge? Your criminal defense lawyer can determine some defenses that are specific to your case, but two main defenses pertain to the aspects of committing the act "knowingly" and "intentionally". Defending against "intent" could be like the above instance of spilled coffee. As for the "knowingly" part, you may be able to show that you did not know that you were destroying evidence. For example, the janitor who shredded documents may be able to prove that they only had night shifts, and that there was no interaction with the parties guilty of embezzling. They may be able to thus prove that they could not know the guilty people, much less what they were doing.
If you are facing this serious charge, then you need to vigorously fight against this and any other charges you may be facing. Call the skilled criminal defense lawyer you need today!