Four successes sees it done. The Osokans are very observant creatures... but they did not get your scent when they came in. You elbow your way through the crowd without stirring up too much notice, though a couple people try to stop you and say hi.
Once you make it backstage, you find your suitcase there as before. The others are out mingling, except Tarinda. The Twi'lek is sitting and drinking a glass of Flaming Wookiee.
"Alek, where are you going?" she asks.
Alek has his pistol in hand faster than the Osokan can approach. You roll two successes in your first shot, catching him across the face with a glancing bolt. You then roll another two successes on your second, blasting into his neck. 6 damage total.
The Osokan, unphased, has drawn a rather unpleasant knife...