### Clue: Head of department's language books replaced by Dutch criminal (9)
### Answer: DESPERADO 
 ### Explanation: Definition: criminal
 **The 1st letter of**(Head of) "department" + "Esperanto"(an artificial international language) with "nt"(abbrev. for the New Testament, the collection of books in the second part of the Bible) **replaced by** "D"(abbrev. for Dutch).