Jasper is the cousin of Rita. After the rest of his family was killed in the invasion of the Zerg Swarm, Jasper was sent to live with his aunt Rita in Quijadas on Choss. She and Rin Shearon took care of him as a surrogate family.
When Rin offered herself to fight alongside Breg Shaw against the mutalisks harassing the town, Rin bet herself a beer that Jasper would voice objections. He did, and asked Rin why. Rin told him that she had to because it was her town.