In Colorado, eavesdropping is a criminal offense. C.R.S. 18-9-304 states:
So, what does this really mean? It means that if you are visibly present and are a principal party to a conversation or discussion, it is legal for you to record a conversation without anyone else’s knowledge that you are making the recording. Under those circumstances, hiding a tape recorder or making an audio recording on your phone while in your pocket would not be a criminal offense. However, it is not legal to record a conversation or discussion if you are not present, or even if you are present but you are not a principal party to the conversation or discussion.
Even if you are visibly present and a principal party to a conversation or discussion and you legally record the conversation or discussion without the other party’s knowledge, your actions are not ethical. Let me explain. When you record someone else in a conversation or discussion without their knowledge, you are making the recording surreptitiously.
Just because surreptitious recordings are legal in some circumstances does not mean that you should engage in such conduct. For instance, lawyers are prohibited from making surreptitious recordings. The Colorado Rules of Professional Conduct prohibits attorneys from conduct involving dishonesty, fraud, deceit or misrepresentation (Rule 8.4), and also prohibits attorneys from making false or misleading statements of facts to third persons (Rule 4.1). The Colorado Supreme Court has stated that an “undisclosed use of a recording device necessarily involves elements of deception and trickery which do not comport with the high standards of candor and fairness to which all attorneys are bound.” People v. Smith, 778 P.2d 685 (Colo. 1989). In fact, Ethics Opinion 112 indicates that a lawyer should not advise another person to record a conversation. Rather, lawyers should only advise of the legal parameters that apply to surreptitious recordings and not suggest making surreptitious recordings. While these standards do not apply to non-lawyers, it does not change the fact that a person making a surreptitious recording is using elements of deception and trickery in doing so.
Simply put, just because something is legal does not make it ethical—and this rings true with regard to hidden tape recorders.