He will not be deported just because you filed for a divorce. If he already has a permanent residence green card, he qualifies for citizenship after having it for 5 years instead of 3 years if he was still married. If he still does not have his permanent green card, but only a temporary one as long as you go with him to his interview for a permanent card even if the divorce is pending he will be OK. If he is already in deportation proceedings then you need to talk to an immigration attorney. Either way filing for divorce and asking for chidl support does not trigger any involvement from immigration.
I agree with the previous attorney. By you just divorcing him especially if the marriage was entered in good faith, he will not lose his green card. In case, he has any issues, he can always go to a good immigration attorney to fight his case. Nonetheless, if has some domestic violence convictions, he might get a hard time. Advice: Get a good criminal immigration lawyer to assist him in case of criminal convictions.
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