I think the prime suspects father gave a false alibi to protect him, which was proven to be absolute lies in court.
There was also CCTC evidence produced by the defence team to support this.
Buddy I bang on and on about this but you should have a read up on noble cause corruption.
Most, if not all MOJ cases appear to have similiar threads (can't think of the right word) running through them.
It's almost like the police has a secondary law book that we don't know about. 
Buddy I think unless you've experienced something like this first hand, I don't think anyone truly understands or believes what the police/CPS are capable of.
I think you are wrong on your last points Steph. I do realise how the truth can be twisted, and has been countless times in the past, of which there are too many to recount.
Thankfully I have never been on the end of this, but I am sure this happens a lot.
Can I politely ask you to remain on topic as I am interested in your plight, but you seem to get distracted at times. Please stop rising to the bait even though it may be hard at times.
It is said that the best form of defence is attack, but at times silence is better.
Tell you what I was interested in was the evidence kit the police used. I did not realise it contained the same flock fibres.
You have an uphill battle Steph, but I wish you well in your quest. If what you say is true, then it is frightening that the murderers of Joan are still at large.