If someone with an outstanding warrant in the USA attempted to fly to a US destination from a Canadian airport with pre-clearance capabilities (i.e. passengers are screened for admissibility to the USA by a USCBP agent PRIOR to boarding the flight in Canada), would they be:
a) allowed to proceed without incident; USCPB doesn't search for open warrants
b) allowed entry but possibly arrested upon landing/deboarding at their US destination (ambushed)
c) denied entry, or
d) taken into custody at the airport? (presumably by Canadian authorities).
In other words, is an outstanding warrant grounds for inadmissibility, and can US Customs have someone detained/arrested in an airport OUTSIDE THE US?