Under federal gang legislation, Congress defined "conviction" to include "a finding, under State or Federal law, that a person has committed an act of juvenile delinquency involving a violent or controlled substances felony." 18 U.S.C. 521. The government might argue that this shows Congress intended certain adjudications of juvenile delinquency to constitute convictions for immigration purposes. On the other hand, since Congress knows how to define conviction to include finding of juvenile delinquency, but did not do so in the immigration context, Congressional intent was to exclude juvenile adjudications as convictions in the immigration context.