- "Why the fuck are we nicking it, then?"
Arthur was born in London in the early 1940's. From a young age he got into safe cracking and became a professional. In the 1960's he became friends with Ronnie and Reggie Kray and began to do jobs for them. He worked with them for years before they were incarcerated. Seen as Charlie Jolson was associated with the Kray twins also, it's likely Arthur was an associate of his as well before his death. Arthur became an expert at safe cracking and continued to do jobs into the 2000's.
At some point he met Danny West. Upon learning he was a safe cracker, Danny decided to recruit him for the bank job. Arthur didn't meet or know anyone else involved in the bank job until attending the meeting at the gym.
Arthur met with the rest of the team at Danny's gym as Danny explained to everyone what the plan was. He introduced Arthur to a man named John, who was the "cleaner" for the job. Arthur mistook the meaning of the word, believing he was a killer, and questioned Danny about this. Danny however assured him that his actual job was simply an ordinary cleaner. Arthur was present when Danny told everyone what to do and he was instructed to enter the bank with John via the cleaners route, along with Sam Thompson. Eddie O'Connor and Errol, who were disguised as security guards, helped Arthur and the rest of the crew up to the top floor of the bank, so Arthur could crack the safe. Arthur cracked the safe while Eddie defended him and took out the guards.
After Arthur cracked the safe, John took off with the icon and made a quick escape. Arthur accompanied Eddie, Errol and Sam and fled the scene. However, things went wrong after the guards chased them. The four of them made it into a room and attempted to escape. Sam and Errol managed to escape the room by climbing up into a vent to escape. Arthur however couldn't, as it was too high up for him. The bank guards broke in and captured Eddie and Arthur. Arthur and Eddie were then taken back to the construction site and were tortured by Alexei, the right-hand man of Viktor Skobel, the owner of the bank they had just robbed.
Alexei tortured Arthur for information, who gave up John. Afterwards, Alexei killed him as was no longer of any use. Alexei prepared to torture Eddie some more as he believed he may know more information than Arthur did. When they discovered the whereabouts of John, Alexei left Eddie in the room along with Arthur's dead body.
Later, Sam and Errol broke into the construction site to save Eddie and find Sam's laptop, which had actually been left back at the bank. Sam released Eddie and the two of them spotted Arthur's dead body lying in a chair in the room. The two of them then prepared to escape.
Arthur's dead body is also discovered later, when Ben Mitchell and backup SO19 officers raid the construction site to look for journalist Jackie Philips. Mitch finds him in the room he is killed in and comments to his boss, Munroe, over the radio, that they found the dead body of an old man and that he had been killed quite recently.
Arthur's death is ultimately avenged by Eddie when he kills Alexei later on.