He was an experienced officer. Circa a quarter of a century under his belt. It stands to reason he would be offay with the 'property register'.
Why did he go to Oak farm to collect the silencer? He was not a SOCO officer. Why did he not take an exhibit bag and label?
So according to you DS Jones was ....
He was an experienced officer.
A relatively junior officer who had no experience of a mass shooting
He was not a SOCO officer
He was forensically aware
Which is it or does it just depend on which argument your forcing?