an offense referred to in section 408(c)(1) of the Controlled Substances Act (
21 U.S.C. 848(c)(1)), committed as part of a continuing criminal enterprise offense under that section, where the defendant is a principal administrator, organizer, or leader of such an enterprise, and the defendant, in order to obstruct the investigation or prosecution of the enterprise or an offense involved in the enterprise, attempts to kill or knowingly directs, advises, authorizes, or assists another to attempt to kill any public officer, juror, witness, or members of the family or household of such a person,