ICE, ATF, and CBP has always been the house for the dregs of federal LEO. It is for the people that fail to get into anything else.

FBI is prestigious because they get the most qualified tyrants, who are smart enough to lie and deceive in ways that are airtight enough that those at ICE take the heat. The surprising thing here isn't the fact that they did it, but that they didn't do the normal way of digging or manufacturing something else to pin on the judge.