Sergeant Bayton was a Terran Dominion marine, and in charge of the group of recruits he had named Meatbag Squadron. He was killed by a baneling explosion in an abandoned Ghost Academy on Tarsonis.
References
Jurgens-Fyhrie, Gavin. "Just an Overlord." (March 21, 2013). Blizzard Entertainment. StarCraft Lore: Just an Overlord Accessed 2013-03-25.