Through his fashion business Arnett worked and became involved with Julia Randall. Like many men, Arnett became quickly enamored and involved with Julia. In turn, Julia manipulated Arnett into resorting to crime and robbery to support her materialistic needs. Julia used her doctor, Harold Stoneman, to acquire the names and addresses of wealthy high society members, while Arnett robbed them with the aid of Wilson "Willy the Wolf" Reade and Jimmy Leblanc.
Through Julia, Arnett also met and fell in love with Heather Swanson and ended his relations with Julia but would still continue committing burglaries on her behalf. Arnett and Heather got engaged at some point and gave her a pearl ring as an engagement ring, which was ironically a stolen item. Eventually, Julia's insatiable demand for money and merchandise was too much for Arnett, and his business went broke in order to support her. Arnett confronted Julia, and told her that he wanted out of their relationship. However, Julia laughed back at him, hence Arnett decided to escape his predicament, by having Julia murdered by Willy and Jimmy.
Events of L.A. Noire
Although Julia's death was made to look like suicide, Cole Phelps began to suspect murder, and would question Arnett and his involvement with Julia. Arnett tried to distract Phelps by stating he was in Marines and fought in Okinawa. However, Phelps saw through his lie and strongly suspected his motives. Phelps and Roy Earle followed Arnett, and discovered he had pawned a rare stolen Faberge cigarette case for a mere $600, and bought a one-way ticket to Mexico City. Arnett did so in haste as he realized that the truth of Julia's death would come out, hence he wanted to escape the city before he could be arrested, and was prepared to leave his fiancee behind.
At his apartment preparing to leave L.A., he was attacked by Willy who then quickly eluded Phelps' custody. Arnett regained consciousness with Heather at his side, with Phelps ready to question him. Phelps presented plenty of evidence of Arnett's involvement, and he was compelled to admit the truth that he committed the burglaries, and paid Willy and Jimmy to kill Julia to get out of her gang. Arnett then revealed that Henderson was actually an alias for Stoneman, who was also involved with Julia and the robberies. With Willy, Jimmy, and Julia killed and Dr. Stoneman later committing suicide, Arnett was the only survivor of the gang, and was sent to prison.
- "If that's all? Heather is distraught. I probably need to get home."
- "I came down here to talk to you - to do the right, to try and help catch Julia's killers - and all I get is abuse. I'm not a criminal, Detective."
Leaving Interview Early
- "Really? That's everything you need? I have more for you, Detective, I'm sure of it."
- "Well, I have a business to run."
- "Terrible news about Julia. Shocking frankly. I'd rather not speak about it anymore, if you don't mind."
- His character is based off of Frank Niles, an associate of the murder victim in the 1948 film "The Naked City".
- Even though his war service is proven to be a lie, there is an M1 Garand hanging in his apartment.