Mark Thompson is the deceased older brother of John and was murdered by the parents of Tyler when he found out that they were thieves when he tried to help Tyler by finding his parents. He died when he was 19 years old.
Mark was a caring older brother that looked after his family and friends. Even when he was working, he ran home to be with John and to play with him when he finished. He also tried to help people that he thought needed it and did as much as he could for them. He was a clever person and was going to go to Uni to study astro-physics.
Mark grew up pretty normally throughout his early life. He went through school with high grades, particularly in the sciences. He met Tyler when he was 16 and learned about how his was abandoned by his parents. He immediately tried to help him by bringing him food and wanted to tell someone but Tyler didn't want to go to an orphanage because he was scared of them. Mark decided to do the next best thing and find Tyler's parents. He spent 3 years balancing searching and studying before he found them. It was his brother's birthday and as he was coming home, he spotted them robbing a building. They saw him and he ran but was chased down and stabbed to death. John visits his grave every year to pay his respects.