Verification of multi-agent systems (MAS) is a huge challenge, especially for those systems where security and safety are of major importance. Verification detects faults, defects and drawbacks in an early stage of software development. Here, we give a formal model for verification of MAS by means of model checking technique. We extend the existing Action Computation Tree Logic (ACTL) with epistemic operators in order to reason about knowledge properties of MAS. We introduce new operators for manipulation on agent?s actions with data. We explain their syntax and semantics for our ACTL-er (ACTL for Epistemic Reasoning), and provide a case study for a MAS system of foraging bees.