Dad arrested at POE w/immigrant visa due to an old warrant...

My dad recently got arrested upon arrival in the USA (he had an approved immigrant visa ,parent of us citizen category) due to an an old warrant which we thought had been dropped. The issue did come up during his visa interview, but they approved him anyway after two years of delay. He is now in jail with an immigration hold, which makes it impossible to bond him out. what are the chances of them revoking his visa anyway after the criminal case is resolved? anyone with similar situations? will he even get a bond hearing if ICE were to pick him up or is he subject to expedited removal since he was arrested at port of entry?

What is the warrant about? Does he have a lawyer? There are waivers for certain things. It depends.

It's an indecency with a minor charge that is utter bogus and untrue basically. We couldn't bail him out bc according to his lawyer, ICE will just pick him up since they have a detainer hold on him.