When it comes to tampering with evidence laws, there's no person or situation that is safe from conviction when the tampering is committed with intent and purpose. In fact, there are separate, detailed statutes pertaining to the tampering of evidence considering whether or not the suspect is a civilian or law enforcement. Furthermore, evidence is categorized by physical evidence and witnesses that could or will be used for criminal proceedings.

Here's a brief, broad breakdown of the statutes (for more detailed information, click the linked statutes):

OBSTRUCTION OF JUSTICE—RS 14:130.1

With the knowledge that it could/will affect criminal proceedings (including investigation, whether in the past past, present, or future), the following are unlawful:

1. Tampering with the specific intent of distorting the results of any criminal proceeding whether a) at the location of the incident or b) at the location of storage.
2. Using or threatening force toward a person or property of another to:
3. influence testimony
4. cause or force withholding of information
5. cause of influence concealment of evidence in any way
6. evade legal process
7. cause prevention of communication with peace officers
8. Retaliating against any involved person, including law enforcement, which results in or threatens bodily injury or damage to property.

Penalties:

Penalties of this crime rely on the sentence imposed on the convicted of a criminal proceeding in which the evidence is involved.

When death sentence or life imprisonment is imposed, the defendant faces a fine of up to $100,000, imprisonment of no more than 40 years hard labor, or both.

When a sentence of hard labor for a time less than life is imposed, the defendant faces a fine of up to $50,000, imprisonment of no more than 20 years hard labor, or both.

When any other sentence is imposed, the defendant faces a fine of up to $10,000, imprisonment of no more than 5 years with or without hard labor, or both.

MALFEASANCE IN OFFICE; TAMPERING WITH EVIDENCE—RS 14:134.2

With knowledge or good reason to believe that the evidence will be subject of any investigation, it is unlawful for a peace officer to take action in tampering with evidence by alteration, movement, removal, or addition of any object or substance.

Penalties:

The defendant faces a fine of up to $10,000, imprisonment of no more than 3 years with or without hard labor, or both.