Its a tough one Nat...I know as I went through the same decsion process about a year ago.
I witnessed people acting suspiciously around our local village post-office whilst leaving work in my car. However, one of them ALSO CLOCKED ME leaving my small office and gave me serious attitude! I drove off thinking about what I had just seen, trying to figure out if it was just my imagination running away with me, when I decided to turn around and go back just to put my mind at rest...where I met what was clearly the get away car leaving the village at speed. I followed it for a while and could see it contained about 3 or 4 guys..and didn't want to get involved (obviously)...so followed for a short while, before they turned into a car park at a train station.
No sooner had I continued up the road to turn around, there were cops everywhere coming from the main town, obviously the Post office guy had called them.
After returning to work to see if anyone else had noticed all this going on (police helicopter over head etc)...I decided to pop down to the post-office to see if I was imagining it all, were the PO master informed me he had just been held up by 3 guys with 'shooters'!
Anyway...eventually the police came to get my details and for a statement...and as you say Nat, started asking if I would give evidence etc.
My concern was that the guy had seen me leaving my small office, where I used to go to work everyday! He would also see my face in Court! UHMMMM!
As it turned out, they had done several local village PO's and the police had shedloads of evidence against them. They where using the money for drugs etc. They pleaded guilty and therefore I didn't have to attend...but I had a few sleepless night thinking about it beforehand I can tell you.
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