[T. P. Pole]

Maybe I'm slow here, but shouldn't a group called Immigration and Customs Enforcement be seeing mostly folks from other countries? How is it a surprise that most of the folks they arrest are from other countries? Shouldn't their number be closer to 100%?

Or is the surprise that we have so many illegals in our criminal system without coordination with immigration to deport them in the first place?

[DB]

I think it means that the remaining 15% were not known criminals prior and/or that they were not here illegally to begin with.

[RGSpincich]

Shouldn't their number be closer to 100%?

Yeah but if reported accurately it wouldn't sound as if illegals were responsible for 85% of all child molest cases.

[lastchance]

The task force was targeting foreign nationals who have been charged with sex crimes. The headline of the article makes it seems as though the immigrant population as a whole were targets making the 85% figure apply to all immigrants.
The article does not say that 85% of illegal immigrants have been charged with sex crimes. It is saying of those immigrants who have been charged with sex crimes 85% of those have been illegal immigrants.
In any case lock em up till they can be deported.