In civil commitment proceedings against defendant, claiming that defendant was a "sexually dangerous person" within the meaning of 18 U.S.C. section 4248, based on numerous criminal convictions arising from repeated conduct of making threatening and obscene telephone calls, district court’s determination that defendant was not eligible for commitment is affirmed as the court appropriately considered the elements required for civil commitment under 18 U.S.C. section 4248, and did not clearly err in determining that the government failed to meet the burden of proving that defendant was a sexually dangerous person.