The Work
http://www2.fbi.gov/hq/lab/html/rrau1.htm
Cryptanalysis
Decrypt manual codes and ciphers found in letters, diaries, ledgers, and other types of written communications, records, and e-mails. Common users of codes ciphers include national and international terrorists, foreign intelligence agents, members, prison inmates, and violent criminals.
Racketeering Examinations
Examine and decode records from illicit businesses, such as loansharking, prostitution, sports bookmaking, and Internet gambling. Such violations are predicate offenses for RICO charges. Examinations may reveal the type of operation, dates of activity, wagering or loan amounts, types of wagers or loans, number and roles of participants, and accounting methods.
Drug Records Examinations
Examine and decode records pertaining to the type of operation, type of drug, quantity of drugs sold or purchased, unit prices, method of payment, transaction dates, roles of participants, gross and net profits, and operating expenses.
From the FBI site, thought I would post as a reminder the kinds of things they might be looking for.