Muse inspirations: Reginald Birch (Assassin's Creed III), and the various 'Prohees'
Reynold Byrd is an undercover Prohibition Agent, and a family friend of the Gunns. He'd known Sullivan since his merchant marine days, and always disapproved of him going into rum-running. Sullivan's activities as a gangster put a strain on their friendship. Driven to stop Sullivan's illegal activities, Reynold deceivingly gained his friend's trust by joining his gang. In reality, Reynold was an informant for the BOI.
When Sullivan had been wiped out by a rival gang, Reynold was relieved, although saddened that his friend was no more. Eventually, Líadan discovered this news, as well as the destruction of her home and kidnapping of her children. Distraught, she sought help from the only person she trusted in these dealings: Reynold. He and his team secretly wiped out the gang in no time, but the result only yielded in the rescue of Harvey. His older sister, Bonnie, was nowhere to be seen.
The loss of Líadan's home and family devastated her. Feeling sorry, Reynold promised to find Bonnie as long as he lived. It was around this time that Reynold 'declared' he'd become a BOI agent in order to find her children (of course, he'd already long been an agent, but he didn't want the Gunns to know that...) Eventually the two married. Reynold helped raise Líadan's remaining child, Harvey, instilling his values of justice into him.
However, little did Harvey know that Reynold was the mastermind behind ransoming him and his sister to the mob, all to jealously spite their father and marry their mother...