Once found guilty by the court, a pirate could be hanged any time ten days after the trial. It was possible for a member of the pirate crew to turn King's evidence and give evidence against his fellow pirates. If he did this, he might get a pardon, but only after the others had been convicted.
On the day of the hanging, the pirates were walked through town in a procession led by an officer carrying the Silver Oar. This showed the authority of the High Court of the Admiralty. They walked to the gallows, which was usually put up in a public place near the water, often at the low-tide mark. The entire event, like all hangings, was a spectacle that drew large crowds. Everyone came to watch the pirates die.
Before the actual hanging, a minister usually gave a sermon, telling the convicted pirates to repent, before being hanged. He would use the pirates as terrible example of what happens to criminals. After the sermon, the pirate was allowed to speak to the people. In their last speech, some pirates said they were sorry, others were rude, and some even told jokes to the crowds. Then they were swung off the cart beneath the gallows, and died.
After the execution, the bodies of the less important crew members were buried face down, below the high water mark. Other times their bodies were left hanging until three tides had passed over them.
The bodies of the worst captains were often soaked in tar so they would not rot, put in an iron framework or chains, and hung from a gibbet by the water's edge. Their bodies would hang there for years, swaying in the wind, until nothing was left. This served as a frightening example to those who thought it might be a good idea being a pirate.
Captain Kidd was not a particularly bad pirate, but his body was treated this way.