David Newcastle was born in Haxby, Yorkshire on September 17, 1966, to Geoffery and May Newscastle. His father was an accountant while his mother was a homemaker, and they had no other children. The family moved to London in 1974 and remained there until recently. Newcastle was an exceptional student who got top marks in history and mathematics. He also was a standout at football, and at one point had a tryout with the Tranmere Rovers (Fourth Division) squad. He was not well liked and was given a rough time by other students because of his accent, which he made every attempt to cover up. Despite this, he had no disciplinary problems, however, or any other red flags.
Instead of going to university, Newcastle chose to join the Metropolitan Police Force. In four years on the force, he was commended several times for bravery, and won three awards for marksmanship. The National Crime Squad took notice and recruited him in 1988. In his stint with them, Newcastle was decorated twice more and demonstrated remarkable bravery and poise under fire. Specializing in hostage situations, he was recommended for promotion twice before the SAS scooped him up for anti-terrorism work. While Newcastle's record with SAS wasn't quite as spectacular as the one he racked up with the NCS, it's still fairly impressive. He was put under consideration for Rainbow as early as 1999. Someone in the SAS later leaked this information to him. From that point on, joining Rainbow became his obsession and he became overzealous in his pursuit of it.
After a hostage rescue in Gibraltar in 2001, he was put in charge of interrogating the prisoners. The interrogation proceeded solo and went disastrously. Of the three terrorists, two needed to be hospitalized immediately afterwards, and the third was dead by the time the session ended. Am autopsy turned up ample evidence of brutality on Newcastle's part, including cigarette burns, broken ribs, and a collapsed lung. SAS ran a psychiatric profile on him and turned up a borderline psychosis. This scuttled any chances he had to be selected for Rainbow, and took him out of the field with SAS. Newcastle didn't take well to the demotion, and was promptly cashiered. Afterwards, he mostly dropped out of sight, even going so far as to cut all communication with his family.
Newcastle eventually started working as a mercenary. He regularly took contracts from anyone around the world, with a majority of it taking place in the Middle East. Newcastle believed Rainbow was the cause of his demotion and recruitment denial and sought to take revenge. He began to stockpile weapons and resources to build his personal terrorist organization. Having studied counter-terrorism tactics extensively, Newcastle concluded that he could modify previous high-profile terrorist attacks so that Rainbow would be unable to stop them, thereby discrediting them and allowing him to expose them for their failure. Newcastle launched his copy-cat attacks from May to July 2004. Following an attack on a Dutch High Speed Train in the Netherlands, however, Rainbow discovered his identity after he was spotted observing the scene by a news helicopter in a nearby abandoned building.
Newcastle grew desperate after Rainbow foiled another attack involving an airport outside of Mombasa, Kenya. On August 11th, he and his men took the UN Secretary-General, Lord Nigel Cameron hostage at his hotel in Milan, Italy. Despite their efforts, Rainbow was able to rescue Lord Cameron without incident. On August 24th, Newcastle and his organization made their last move at the 2004 Summer Games in Athens and hoped to replicate the 1972 Munich Massacre. Unbeknownst to Newcastle, however, Lord Cameron had overhead his plan during his time as a hostage. This allowed Rainbow to give Olympic security a heads up about the attack and coordinate a plan to ambush them at the Olympic village. Unfortunately, Olympic security sprung the ambush on Newcastle and his organization before Rainbow was ready to provide support. This resulted in the death of two Olympic security personnel and an unknown number of them being taken hostage at the nearby Convention Center. Rainbow was able to successfully rescue all hostages and neutralized Newcastle and his remaining forces.