Patrick Labyorteaux, who played the "Bookie" Olev Kozlov, was also part of the main cast of Donald P. Bellisario's JAG (1995), the series which spun-off NCIS (2003). He played Bud Roberts, a JAG lawyer who also appeared in several NCIS episodes.
DCIS - Defense Criminal Investigative Service, the criminal investigation division of the Office of the Inspector General of the United States Department of Defense (DoD). DCIS is tasked with investigating crimes committed by DoD personnel and also protects the security of the United States military by investigating cases of fraud, bribery, and corruption; preventing the illegal transfer of sensitive defense technologies to proscribed (forbidden) nations and criminal elements; investigating companies that use defective, substandard, or counterfeit parts in weapon systems and equipment utilized by the military; and stopping cyber crimes and computer intrusions.