At some point between May and October 2017, Sam Armand was appointed the district attorney of Star City. In this position, Armand represented the city in a case against Oliver Queen. However, following Oliver's arraignment, Judge C. McGarvey allowed Oliver free on a $5 million bail and $500,000 bond.
Armand approached police captain Kimberly Hill, a fellow member of Ricardo Diaz's payroll, claiming he finally had enough evidence to run Oliver into the ground and end his term, asking for the full backing of the police force.
It is later revealed that the evidence is actually Roy Harper, who was found and captured by corrupt Star City Police Department officers under Diaz's payroll, with trying unsuccessfully to get him to testify in court that Oliver is Green Arrow. Roy is eventually rescued by Team Arrow, leaving Armand with no strong case against Oliver.
Armand still refused to drop his case against Oliver. After Anatoly Knyazev was arrested, Armand had him released due to no arrest warrant and because of his allegiance to Ricardo Diaz. Armand and Hill were later summoned to the mayor's office by Oliver who confronted them about them being on Diaz's payroll. Armand revealed that his son had cancer and he needed Diaz's money. When he and Hill refused Oliver's protection for their families, they were fired. Due to this, the two went to news outlets, broadcasting their firing as a ploy by Oliver to obstruct the investigation into him being Green Arrow.
After Oliver used a device made by Felicity Smoak to copy all of Diaz's files, he gave a list of every individual under his payroll to F.B.I. agent Samanda Watson. Samanda had all of Diaz's allies arrested, including Armand.
Similar to Adrian Chase, Sam was concerned about cleaning up the streets of Star City and was concerned about the welfare of the citizens of Star City rather than his approval ratings, but this changed when Sam's son developed stage four leukemia. Even with the city's insurance, Armand still couldn't afford to pay for the treatments. This forced him to work with Ricardo Diaz, since Diaz promised Armand funds for his son's treatment. Unlike Kullens and C. McGarvey, who were working with Diaz out of greed, Armand was motivated to bring down Oliver Queen and work with Diaz as a father to his son.