Bank Job

At first glance, the robbery in a small bank branch doesn't seem overly mysterious. After all, the CCTV footage clearly shows a masked robber threatening bank clerk Jim Carling with a gun before disabling the cameras.
However, the robber knew a bit too much about the inner workings of the bank, so Detective Inspector Helen Shepherd quickly suspects that the robber had inside help. But who of the five bank employees is the insider? And what happened to Jim Carling after the robber took him hostage?

This is a crime novelette of 9300 words or approx. 30 print pages altogether.