How legal is this?

Factual Questions
1

US arrests Wife and Daughter of an iraqi war criminal

Just curious, how legal is it to arrest someone merely for having a family connection to a criminal? Obviously, the US wants to question these two in an attempt to track down Izzat Ibrahim al-Douri, but shouldn’t they have been taken in for questioning, rather than being arrested? Doesn’t arrest imply a specific charge, or is there a ‘general’ arrest?

Am I right to assume this would never happen within the US? Is it a case that at times of war, the due process is quite different? (Even if thats true, didn’t the war end months ago?)

2

Wouldn’t they at least be guilty of aiding and abetting? IANAL though so this is a WAG.

3

IANAL etc.

Would this be legal in the United States? Probably not unless there was probable cause to believe that the wife and daughter were accomplices or “material witnesses.” But under the PATRIOT Act, who knows anymore?

Is it legal in an occupied territory under martial law? Sure. The US military makes the rules and what the military says, goes.