; and (4) the term serious crime means— (A) any serious violent felony as that term is defined in section 3559(c)(2)(F) of title 18, United States Code; (B) any serious drug offense as that term is defined in section 3559(c)(2)(H) of title 18, United States Code; (C) an offense involving the theft of $500,000 or greater; or (D) an offense consisting of racketeering, bribery, child pornography, obstruction of justice, or perjury, that an agent or employee of the relevant law enforcement agency has reasonable grounds to believe that an informant has committed.