This article is from the NYPD Blue FAQ, by Dave Chapman, Alan Sepinwall and Jeff Knapp with numerous contributions by others.
He's currently undercover in the New York mob -- sort of. :)
Nick Turturrro has taken some time off from the show to play
the lead in NBC's miniseries on the life of noted mob hitman
Sammy "The Bull" Gravano, whose testimony eventually put mob
boss John Gotti in prison. Martinez was temporarily written
out in the episode "You're Under a Rasta," where he threw out
his back. Nick should be back by season's end.