I totally botched my previous post. My apologies. In an attempt to clean it up:
Why does the public need to know right now?
If they are trying to make a perp feel comfortable and that they aren't looking to charge him or her with anything, then they may not say "foul play". That is a loaded term psychologically speaking. I've seen several "interrogations" where they convince the perp that they're on their side, that things can happen "accidentally", that they know the person didn't mean to do anything wrong, etc. Using the words "foul play" can ruin that flow.
In a way this reminds me of the first and second question Border Control asks you if you have ever left the country and drive back in. I lived in San Diego for a few years and my friends and I would travel down to Baja for a fun night. Sometimes we drove. Every single time we drove back into the U.S., the first question was, "What country are you a citizen of?" Seems like a totally random question to ask. Next question was the serious one, "What were you doing there and how long were you?". I asked a BP Officer about it once, he told me it throws people off. Easier to spot the ones lying when you come back with the second question. The determining question.
I'm sure there's a reason and method as to the 5-10 minutes, etc.