Buffyverse/ C.S.I. crossover

After S7 Buffy, and S5 Angel, Xander went to Africa. There he was turned into a child with all of his memories still intact, as the result of some demonic intervention (your choice), Xander is sent to live with his parents, in Las Vegas. There he witnesses his father killing his mother, or the other way around, again your choice. Just some traumatic method of getting rid of Xander's parents. He somehow hides from the cops when they come to check the crime scene. When the C. S. I. show up, Nick or Grissom must be included, he is found by one of the C.S. I. ...