I work in a small, family-owned establishment.
On the payroll, there’s me, 6 other staff, the owner and his bookeeper.
Then there’s the owner’s DP and a few of their family members who come and go from the living space upstairs.
Every week for the last few weeks, there’s been notes left from the bookeeper stating that the till was short the previous day. Sometimes it’s clear that someone has just made a mistake while ringing through an order - £4.30 short for example because someone hit the button for a pint of cider twice. It happens.
But more recently, the till has been short by some pretty even figures 
Like over the weekend, it was an even £20 short. And the week before, an even £30 short. Nothing on our food menu or in the bar costs a round figure, except bar snacks. So unless someone’s been ringing through 30 packets of peanuts and not taking for them, my gut instinct is that the cash has been nabbed.
Now it’s not me. And 3 of the other bar staff have been working there for years and it’s never been a problem until now, so I don’t think it’s any of those 3.
My suspect pool are the 3 newer staff and the family members (a few of them teenagers) who come and go.
It’s bugging me. It’s putting the management in a bad mood because they are being stolen from. And it makes me a little nervous about my own belongings while I’m working. The owner of the place is the kind of guy who would move the Earth to help any of his staff out if we needed it, so the idea of someone stealing from him is horrible.
Do I go all Sherlock Holmes and try to catch whoever it is out? Or just drop it and hope they get caught 