I have two questions to apply to you with:
1. Can an 'evening' be 'distant' if I recall him? Can I place the words together as a substantive group?
2. Can I say: 'execution by shooting' or just an 'execution'?
Thanks in advance.
1 I suppose you could say 'distant evening', but there's a very strong collocation between the words 'distant' and 'memory'. So I think you'd be more likely to say 'I have a distant memory of that evening' [an evening's not a he - I guess you knew that already. ]
2 You'd normally just say 'execution', and most executions by shooting would be called 'execution by firing squad'. Only an execution by shooting, but not involving a firing squad, would be referred to as an 'execution by shooting'. (In crime stories, though, you often come across the expression 'execution shooting' - which is always criminal: He was shot from point-blank range in the back of the head - looks like an execution shooting.)