Multiple reports say comedian Conan O'Brien stopped his party guests from calling the police on Nick Reiner, who had apparently become agitated and combative during the Christmas Party at O'Brien's home the night before film director Rob Reiner and his wife were stabbed to death in their own home.

Multiple attendees say they witnessed Rob Reiner 78, and wife Michele, 70, having a heated argument with their son Nick at Conan O'Brien's holiday party on Saturday night.