Turks and Caicos

I have a colleague travelling to Turks and Caicos tomorrow on American Airlines via Miami on one PNR.

I'm assuming he'll have to go thru US immigration and collect baggage and thru customs before re-checking in for final leg from Miami to Turks and Caicos. Or as they are transiting thru US would he not not need to do this.

Is anyone able to confirm this.

Yes he will have to clear immigration and collect bags to go through customs even if they are tagged all the way through.

Does he have his ESTA? Because even though he is only passing through the US he still needs one.

Thanks very much Tontybear
This is what I assumed. Yes he has Esta.

After passing thru customs, just needs to head for transfers?

Its a requirement on all non-US origin transit passengers.

Thanks very much Tontybear
This is what I assumed. Yes he has Esta.

After passing thru customs, just needs to head for transfers?

At most US airports there is a bag drop desk between the customs point and the exit where you hand your bags back over. There may be specific airline desks or just a generic one. If not he will have to lug them to the AA check-in desks and check-in again as normal.

US airports generally don't have the airside transfer / connections processes we have.