The Tenth Circuit has concluded that the sexual abuse of a minor aggravated felony contains a mens rea requirement. Thus, a conviction for unlawful sexual activity with a minor in Utah (a strict liability offense) does not fall within the ambit of the aggravated felony conviction. The court declined to defer to the Board of Immigration Appeals' decision in Matter of Rodriguez Rodriguez, finding that the decision did not address the issue of whether the aggravated felony provision included a mens rea requirement.
The full text of Rangel-Perez v. Lynch can be found here: https://www.ca10.uscourts.gov/opinions/14/14-9566.pdf