It's possible you have a potential on the earth in the building have seen this before , it was resolved by correcting a fault in a socket , however tingling on the bncs maybe a side issue, as those lines or bars or whatever we call them "shouldnt" cause that , maybe it's the power unit, I have seen toroidal transformers cause this in a similar way
As above stick a battery on them and see what happens , if DVR is 12v input then even easier you can stick it all on a battery