Decker is the true power in the Hub, and little happens thereof that he is not aware. He is outwardly calm, even placid, and quite patient; he is also quite ruthless. He possesses great intelligence and speaks in an eloquent way, contrasting with his brutish appearance. He seeks to control the entire water distribution business, which would establish him as the de facto ruler of New California, via the Far Go Traders, a merchant company he controls from behind the scenes.
He is wary of threats to his position, including the Children of the Cathedral, whose attractive preaching and aggressive expansion endangers his operations. Likewise, he also looks for a way to control the Hub police, whose head, Justin Greene, is less corruptible than his father.
Some time before 2161, Decker captured an initiate of the Brotherhood of Steel who was visiting the Hub and held him prisoner in Old Town, torturing him to get information on the Brotherhood of Steel. The player can rescue the initiate as part of the "Rescue Initiate from the Hub" quest given by the Brotherhood.
Take down Decker: At any time during or after the above quests, he can be reported to Sheriff Greene. The player will be asked to assist in taking him down; as expected, neither Decker nor Kane will be too pleased.
Decker's death is the knell of the Underground - his absolutist control of all criminal activities within the city basically means that there is no one to succeed him; the Hub police can easily pick off any criminal elements without fear of retribution.