The only reason I would support arming residents in the banditry-prone areas is to offer self-defence. The bandits are well armed and are not primarily against the armed security officers but unarmed residents who need to be empowered to secure themselves because they are helpless and unprotected from the bandits.
When residents are armed, they can thwart some attacks and protect their property because they rely on security men who are not entirely on the ground and can offer protection immediately it is needed.