ACPO non-compliance?

I was taught that this was a balance between the probative value of a piece of evidence and it's prejudicial value, a subjective decision on the part of the presiding judge.

It seems to me (but I may well be wrong, as always) more similar to the US concept of "exclusionary rule" and/or "fruit of the poisonous tree"
http//en.wikipedia.org/wiki/Exclusionary_rule
http//en.wikipedia.org/wiki/Fruit_of_the_poisonous_tree

I thought that the OP question was more about the technical methods (and this is what mainly the ACPO guidelines are about) of collection/discovery (and related chain of custody/repeatability) than about something related to the "fairness" of the evidence and legality of it's seizure.

BTW, and possibly OT 😯 , what I often happen to see "between the lines" is a non integral compliance with points 6.5.4 and/or 6.6.2/6.6.3 of the ACPO guidelines, which may well be considered by the Court to be excluded according to that Section 78 provisions.

Some time ago I mentioned a document by the Federal Court of Australia
http//www.forensicfocus.com/Forums/viewtopic/p=6559980/#6559980
That you can get from here (direct link)
http//www.fedcourt.gov.au//pdfsrtfs_p/practice_notes_cm7.rtf
that addresses nicely this aspect.

jaclaz