united-states criminal-law police self-incrimination
During an investigation, can a US law enforcement officer say something is legal if it is not?
<p>When investigating something that has already happened, can a US law enforcement officer say "x is perfectly legal" to get someone to confess to having done x (which is not actually legal and someone will be prosecuted for x if they (or a co-conspirator) confess to it).</p>

<p>In general, police are allowed to lie. Certain statements are taken to be self-enforcing, for example "You are under arrest" <em>means</em> that you are under arrest, "Yes" in response to "Am I free to go" is taken to mean that you are free to go and therefore if you leave, they can't beat you for attempting to escape arrest.</p>
