The bunco squad is those policemen who investigate confidence swindles. In use from the 40's through the 60's. Not usual among law enforcement today.
The original "bunco" was a dishonest gambling game. Perhaps a variant of banco, from Spanish banca, which is a card game similar to "monte".
Eventually the word evolved to mean swindling or fraud of any sort).
Now applied to various groups of poseurs who appear with their wack front.
"The Bunko people are really carrying a needle for the Rube"--W.S. Burroughs, Naked Lunch
Look... Here comes the bunco squad in their rice burner CRXs.