This squad exists by chicanery! (5)
I believe the answer is:
fraud
'chicanery' is the definition.
(fraud is a kind of chicanery)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for fraud that I've seen before include "Swindle" , "Deliberate deception to gain benefit" , "Fiddle" , "Diddling" , "Imposter - deceit" .)