Patrick O'Doyle was an orphan and never really knew his parents. O'Doyle grew up in foster care and was quite unremarkable at school and sports,but upon graduating he took the only out he had and enlisted in the United States Marine Corps. Through the service he finally had direction to his life and an outlet for his anger and energy that school and wrestling could never give. O'Doyle reveled in his training. He excelled in hand to hand combat and weapons training and after boot camp; was deployed 3 different times with 27 confirmed kills.
After 8 years in, O'Doyle was ready to re-up for a third time when he was recruited by Murray Longworth to do "gray work" for him. Murray had Patrick O'Doyle erased. O'Doyle spent the next 11 years killing all over the world. He would be dropped into a country and eliminate what ever target he was tasked with through means of jungle work or urban penetration, his specialties. On three separate occasions Murray had asked him to volunteer for missions that held no certainty of returning and Patrick O'Doyle had accepted them all. On his last mission of the three he was captured. O'Doyle was questioned and tortured. After his captures burned his ear off; mass confusion and a drone strike gave him the opportunity to escape. When O'Doyle returned Murray was no longer able to use him as a front man for the jobs O'Doyle had been doing for over a decade because his scared face no longer allowed him to blend in. This lead Murray to place him in the Department of Special Threats. Little is known about O'Doyle's time in the DST, but we know he was active during the events of Ancestor and Pandemic seeing as how Murray Longworth told Colonel Paul Fischer (Ancestor) to recruit him for the DST. It is also eluded to in Earthcore that because of budget cuts; he was released from service shortly after the events of Pandemic.