O'Brien was born in New York City, New York and has started his stunt career as a member of the live car stunt group "The Hell Drivers". Since 1986 he performed stunts in over 400 television series and films and has also started a directing career beside his credits as stunt coordinator. He is married to Cindy and resides in Thousand Oaks, California. O'Brien is the owner and president of "Variegated Enterprises, Inc.", a company for stunt and stunt rigging equipment. Currently, O'Brien is serving as Treasurer of the Stuntmen's Association of Motion Pictures. [1]