There are a number of synonyms that can be used to describe a Detective Chief Inspector (DCI). One possible option is "Detective Superintendent," which is a rank equivalent to a DCI in the British Police Force. Another synonym is "Detective Inspector," which is a lower rank than a DCI and is responsible for leading investigations under the supervision of a DCI. Other related terms include "police detective," "investigator," and "law enforcement officer." In general, these terms all refer to individuals who are responsible for conducting investigations into criminal activity and bringing perpetrators to justice.