The woman, a citizen of Mexico who was living in El Paso had been driven to the courthouse by a victim’s advocate from the Center Against Sexual and Family Violence, a shelter for victims of domestic abuse where she had been living.The episode prompted David Koon of the Times to put a question to Wendell Griffen, a circuit judge in Little Rock, about immigration officials' stationing themselves at courthouses.
She left under arrest.
“This is really unprecedented,” El Paso County Attorney Jo Anne Bernal told The Washington Post.
It was the first time in her 23 years at the courthouse, Bernal said, that she can remember ICE agents making their presence known during a protective order hearing. The agents had come to stake out the woman, identified by her initials I.E.G., because, Bernal speculates, they likely received a tip from the only other person who knew the time and place of the hearing — the woman’s alleged abuser.
The short answer to your question is not one I take pleasure making. However, if a law enforcement officer (LEO) has probable cause to make an arrest and is in a place within his/her jurisdictional authority, then the LEO can do so consistent with the Fourth Amendment (which protects against unreasonable search and seizure). Therefore, if ICE agents position themselves inside a state courthouse and have probable cause (meaning an objective basis) for believing someone may be an undocumented immigrant, that would be sufficient to permit them to arrest (detain) the suspected undocumented person.
I'm unaware of any legal authority that allows state officials to bar federal agents from entering public offices to engage in surveillance of the public in order to locate and arrest persons they have a probable cause to arrest. That does not mean ICE agents would be allowed to detain and interrogate people without probable cause.
The problem for the undocumented community is that ICE apprehension and detention actions (arrests) in these situations are likely to occur outside the presence of a judicial officer, and the suspected undocumented person probably will not be able to seek judicial protection in time to prevent being detained.
I agree that this practice will undermine access to the courts to undocumented persons, and will subject undocumented persons to increased victimization. Undocumented immigrant workers are already susceptible to increased risk of robbery by thieves who count on them to not report being robbed to law enforcement, for fear of having their undocumented status discovered. Allowing ICE to hang around courthouses and courtrooms will result in undocumented persons who are witnesses and victims not showing up for trials, thereby hurting law enforcement efforts aimed at discouraging and punishing persons who steal from and otherwise prey on our undocumented neighbors.