Questioning the suspect
There will probably be several interviews - and these days you should have transcripts of the tapes of those interviews.
You should list the times of each interview and the lengths. - sometimes it is even worth counting the number of words in an interview because the police sometimes stop the tape during an interview in order to "offer some advice" that the prosecution might later be embarrassed about.
You will find that there may well be significant gaps between the various interviews. Bear in mind that the police are working hard in these gaps. They are trying to discover more evidence, based on what their suspect has told them. Or they are trying to break the suspect's version of events, trying to prove that the suspect is telling lies. So who did they actually visit - or re-visit - in these gaps? And how significant is the evidence that they discover at these times?
Next, list the police questions. Why? well, the police questions are based on two sources. First, they ask questions about subjects where they already know the answers. If we have read the statements from the witnesses they already have interviewed, we should be able to identify these questions. The objective of these questions is to try to catch the suspect out in a lie. This is the main way in which police break interviewees down - the other methods are
b) over-stating the strength of evidence against he suspect - even to the point of telling lies and
c) "good cop bad cop" - where they hope to gain the interviewee's confidence.
If we identify the questions based on what the police know already, then what remains are questions of which they do not know the answer.
They will argue that such questions are put so that the suspect can clarify matters and thereby, perhaps, prove an alibi. Others might say that they are trying to get the suspect to incriminate him or herself.
What is important to us here is that this analysis gives us a list of what the police do not know - or are unsure about. Here then is a list of their weak points. If they charge the suspect without getting sufficient proof in these areas, then they will try to do this after the suspect is charged. So who was interviewed by the police after the suspect was charged?
This is the point at which some evidence vanishes - because it does not fit the scenario on which the police have charged their suspect. This is the point at which witnesses are sometimes re-interviewed so that their version of events might be "got straight" - or changed in order to fit the essentials of the police case against the suspect. These witnesses are those whom you will want to interview. You should not do so however - for reasons explained elsewhere.
What you should do is find other witnesses to the matters contained in the statements given by these witnesses. Such is the nature of a police investigation that these witnesses might even be found elsewhere in the statements handed over by the prosecution. It should be your first area of research.
It is worth looking again at the judge's summing up at this point - which witnesses did he rely upon for the evidence at the key points you have identified? You may be beginning to find "fresh evidence"!