### Clue: Nothing fits with information detectives last gave on killing (8)
### Answer: GENOCIDE 
 ### Explanation: Definition: killing
 O(letter representing 0/nothing) **contained in**(fits with) [GEN(information/facts) + CID(abbrev. for the Criminal Investigation Department consisting of detectives)] + **last letter of**(last) "gave".
Defn: … of a large group of people, especially a particular nation or ethnic group.