This article is a stub and does not have enough relevant information. You can help by expanding it. Peter O'Brien was the writing lead for Halo: Reach. He was raised in Mill Valley, California. SourceEdit ↑ Halo: Reach credits External Links Edit Peter O' Brien on IMDb Retrieved from "https://halo.fandom.com/wiki/Peter_O%27_Brien?oldid=1809021" Categories: Stubs The Real World Bungie Staff Add category Cancel Save Community content is available under CC-BY-SA unless otherwise noted.