Legal Question in Immigration Law in Iowa

They can do it any time when it's convenient for them. Usually, soon after the county jail notifies them and they serve him a Notice to Appear.

If ICE placed a detainer to hold your husband after he has completed his time for the owi, ICE has 48 hours to pick him up excluding weekends and holidays. If ICE does not pick him up from the jail by the 48 hour period, the county jail should be notified that it will be holding your husband unlawfully. Advise that the jail warden read the detainer document and it will advise that ICE has a 48 hour period to get the detainee. Now, if the question is when do they "have to come get him?" The answer still remains within 48 hours of his release from his criminal time served. Unfortunately, few jails understand the regulations, so you may end up simply arguing enough so that ICE will eventually have to come and get him or the jail will have to release. Good luck.