'NCIS' Season 13 airs 300th episode on March 15th; Team re-eaximines ambush of Special Operations snipers in Iraq
'Murder the First' alum Taye Diggs has been cast as Marine Gunnery Sergeant Aaron Davis in 'NCIS' Season 13 and Laura San Giacomo returns to reprise role as Doctor Grace Confalone. Also, CBS has released the official plot for the 300th episode.