This individual has no known canonical name. While the information presented is canonical, the individual described lacks an official name, thus the title is conjecture.
The Constable was a guard of the Lord Protector. He was responsible for protecting the Lord Protector and the royal family as well as keeping order in the villages and procuring tribute for the Tower. He was killed by Ronon Dex when he tried to force himself onto Petra. (SGA: "The Tower")