The Nightstinger, a blaster rifle manufactured by Xerrol and officially designated the Nightstinger sporting blaster rifle, was an illegal weapon favored by the Galactic Empire's clandestine operatives for covert, long-range engagements.
Compared to other Imperial blasters, the Nightstinger had drawbacks. It could only fire three to five times before needing a blaster gas canister replacement, because it used a lot of energy for each shot. While it had some advantages, the difficulty in obtaining and refining the gasses, which cost approximately one thousand credits per canister, made it somewhat impractical. Its key advantage was firing an invisible energy bolt, making it ideal for assassinations.
The Empire used a clever tactic where a sniper would use the Nightstinger to fire invisibly at a redirection crystal, which would force Tibanna gas through a blast tube, firing a visible blaster bolt. The blast tube would be destroyed after a single use, leaving only small debris identifiable mostly by Imperial Intelligence. Using this method, an agent with a Nightstinger could frame a target for murder with the right preparations.
Han Solo and Rayl'skar, the Askar clan leader and a Bothan dignitary, were framed by Imperial agents from the "Vengeance" cell using this method. They were made to appear as if they had attacked civilian rioters on Bothawui. However, a Noghri serving as a guard to Princess Leia recognized the tactic.