In the brief (and likely edited plea) for Blaise's, return, Listen to what, Mum say's. There are some +'s (positive's), some -'s (not so good) and some, Neutral, (indifferent).
The first interviews are vital to discern one's state of mind and whom is priority.
LD (Linguistic Disposition)
For example. If we look at the, CS, case. Mums LD, was in the positive in her initial interviews, and as we know, C was found and Mum wasn't involved.
LD:
We do not want to hear anything negative however subtle about the victim.
We do want to hear concern of what the victim maybe going through. Are they warm, are they hungry, are they thirsty etc etc....
We do not want to hear what the guardian is feeling, going through (unless asked) because priority is concern for the missing.
We do not want to hear praise for LE (unless asked) when they have not located the victim.
Linguistic empathy. This is to say, i wouldn't like anyone to go through this. (Positive)
We want to hear the victims name early and often. We want to hear the pronoun "my" taking ownership, showing closeness and not distant, unless speaking alongside a partner, parent (We") Even then, the expected (especially from a Mum) should be "My".
All these are just some things to look out for. IMO.
More statements needed.
AMO