Double-crosser and Shill

Double-crosser noun - One who betrays a trust or an allegiance.

Shill and double-crosser are semantically related In some cases you can use "Shill" instead a noun phrase "Double-crosser".

Shill noun - A decoy who acts as an enthusiastic customer in order to stimulate the participation of others.

Double-crosser and shill are semantically related in informer to police topic. Sometimes you can use "Double-crosser" instead a noun "Shill".