If you are totally innocent withholding information may result in a killer or other violent crimial walking free to commit more violent crimes.
Common sense is that just because a right exists it does not have to be asserted and if one needlessly asserts a right and justice is not allowed to place all of society may suffer. How would your child feel if he or she withheld information that would have convicted a violent criminal and the freed criminal committed one or more murders.
You and I are speaking about two different things. One is if your child may be suspected of a crime. The other is if your child is a witness to a crime/or knows about a crime that has occurred or is going to occur. Both examples are extremely different. If I am pulled over for a broken tail light, I will not submit to a search. However, if I see a car mow down a pedestrian and obtain the license, I am a witness and will provide the information.
A child should NOT talk to the police without informing his or her parents first. No way, no how. Not if he is a witness or a suspect. A parent needs to be present during any and all interviewing. The same child that may go to the police because he “heard” someone was going to commit a murder, may be the same child that is interviewed as a part of that murder. Think it doesn’t happen? It does.
With respect to “may send the signal one is attempting to hide something”. An arrest can’t be made on a signal. A conviction cannot be made on a signal. For what it is worth, even if my child knew about a crime in the most innocent manner, you would bet that I’d hire an attorney to be present during the questioning.