The Johnson City Police Department (or JCPD) was the law enforcement agency in Johnson City on planet Cestus III. The JCPD had their headquarters within Johnson City, and maintained its own staff of scientists for examination of forensic evidence.

In 2381, JCPD Sergeant Hildegard Silverman arrested Torethirala zh'Vres, alias Altheria zh'Ranthi, on charges of fraud and conspiracy, after it was discovered zh'Vres altered her identity and falsified the logs on her ship, the Kovlessa, to indicate they had been to Zalda. (ST novel: A Singular Destiny)