Complex sentence: Dr. Thomas was one of Jason's doctors ten years earlier after he was in a car accident, and it is shown through various flashbacks that in 1996, A.J. hired Dr. Thomas to kill Jason while he was in a coma after the accident.
Split into simpler sentences: Dr. Thomas was one of Jason's doctors ten years earlier after he was in a car accident. It is shown through various flashbacks in 1996, A.J. hired Dr. Thomas to kill Jason while he was in a coma after the accident.