'CSI: NY' Star Carmine Giovinazzo -- Pleads GUILTY in DUI Case

"CSI: NY" star Carmine Giovinazzo -- who plays Det. Danny Messer on the show -- has pled guilty in his Arizona DUI case -- but chances are he won't spend a single day behind bars ... TMZ has learned.

We broke the story ... Carmine was arrested in Scottsdale on Jan. 21 at 2:40 AM after cops say he was drunkenly swerving all over the road in a Jeep Wrangler.

Now, we've learned ... the 39-year-old actor struck a deal with prosecutors in which he agreed to enter a guilty plea ... and in exchange he was ordered to complete an alcohol training program by May 3.

There is one catch -- if Carmine fails to complete the program by the deadline, he'll have to spend 10 days in jail ... but c'mon, who would possibly screw up that deal???

Stay tuned ...