Baseline values for metal detection readings associated with an item inserted into an infeed mouth of a depository are obtained before the item is pinched on a pathway of the depository. The baseline values are adjusted by additional readings obtained when the item is pinched on the pathway for transport. The adjusted baseline values are processed with calculated values from ongoing and fluctuating current readings to determine at least one final value. A determination is made as to whether the item includes at least some metal based on comparison of the at least one final value and a predefined value.