It matters NOT A JOT what are the translations. The Psalms, beautifully worded though some are, are, in reality, no more than Biblical 'pop' songs. They are not the 'Word' of God. There is nothing specifically written -which is God's word- which proclaim that he will forgive murder committed by one of his followers. That you say "Whether or not God does actually forgive murderers is a whole different debate..." suggests you may have have asked 'your' vicar a question in isolation to get the answer you were seeking.
I think you misunderstand me Jane
I am not saying that God does or does not forgive murder ...
I am saying that many Christians believe that he does ...
And they believe that Psalm 51 is relevant ...
Because of line 14 " Rescue me from the guilt of murder, O God, the God who delivers me!
Then my tongue will shout for joy because of your deliverance."
It might not be what you and many other Christians believe but it is what very many Christians believe ...
I already knew this - the Vicar confirmed it ...
And the particular translation does have relevance to this case ...
The Court of Appeal looked at whether Psalm 51 was relevant ...
The expert Dr Gillingham does not accept line 14 relates to murder because her translation that she believes in is worded differently ...
This was a very bad mistake ...
She should have told the Court of Appeal that different Christians interpret line 14 of Psalm 51 differently ...
As you can see from the link I gave you many Christians translate it as murder ...
She should have told the Court there are different translations and interpretations - she did not ...
She should have shown them the modern translation I have shown you ...
Had the Court been shown this version of the Bible they would have viewed this point differently ...
Psalm 51 is famous for being one of the most differently translated passages in the Bible ...
Jeremys lawyers should have employed a different expert ...
If they get back to the Court of Appeal then they should do exactly this ...
There are plenty of religious experts who could show and explain this to the Court of Appeal properly ...