C.I.D. Season 1 Episode 93 The Man with Many Names - Part 1 1998

When a businessman is murdered in his own home, CID is called in. An investigation reveals a bloody knife and a calculator on the scene of the crime. Finding two glasses on the table, CID deduce that the businessman met someone before his death, and an inspection of his diary reveals that he had only two appointments set for that day, one with a car salesman. But a further investigation reveals that the car salesman has never met this man, and that the business card the man had for the salesman was in fact fake. With few leads to work off, CID be able to figure out who the murderer is?