Death sentences authorized by the Imperial government, known as Imperial Death warrants, were carried out by individuals such as bounty hunters, Imperial Assassins, and various other Imperial operatives.
One of the factors that led Senator Garm Bel Iblis to ally with the Rebellion was the existence of Imperial death warrants targeting him and his family, following his rescue by Galen Marek.
Stormtroopers stationed on The Wheel attempted to execute an Imperial death warrant against Chewbacca during 0 ABY. Later, in 3 ABY, Darth Vader could not cancel the warrant that was out for Payback, but he did manage to grant a temporary postponement.
Following his involvement in the rescue of Han Solo from Jabba the Hutt, R2-D2 accessed Jabba's palace computer system and fabricated evidence suggesting that Imperial death warrants had been issued for the crime lord's highest-ranking remaining subordinates. This caused a mass exodus from the planet, which in turn created a distraction that enabled Artoo, Solo, and their fellow Rebels to slip past an Imperial blockade.