A kingpin is the head of a large organised criminal group, feared by their subordinates and the public, respected by others of their standing. Despite this they must always be sure to surround themselves with trusted persons, as there is always someone looking to usurp them.
As head of a criminal group, they are very wealthy and powerful, but to be seen outside of the criminal group requires a legal appearance, some are even nobles or respected members of society.
While players are generally free to select a citizen role as a background, they should check with the Dungeon Master to make sure it fits within the local area, other party members and does not conflict with the intended adventure.
Citizens have proficiencies in weapons and armour relative to their type and region, so it is not included in the above information, and players do not gain any proficiencies from choosing a citizen background.