There is no Mapelton Casino in Connecticut. Connecticut has just two casinos, Foxwoods and Mohegan Sun.
In referring to Binh's interaction with other Marines in his unit, Special Agent Gaines makes the repeated error of referring to them as his "fellow officers" as though they were all together on a police force. "Officers" in the military alludes to individual above a certain rank. The proper reference would be, "fellow Marines" or less formally "fellow servicemen."