As a general rule there won't be any government controlled police forces and armies. Each community will set up its own means of defense. And, when necessary, multiple communities will band together to defend their rights.
Guns will not be items that individuals go out and get on an impulse and keep to themselves. Much rather, communities will train their members in defense and will supply them with weapons together with the necessary instruction in their safe handling.
This is part of the principle that power comes from below, from individuals and communities, and flows to bigger and bigger groups and aggregations of power. There will not be any power hungry public representative who can take control of an army or police force and direct it against the people. The army IS the people, and much rather the people will take away previously assigned power from anybody who misuses their position of trust.
No region can be conquered by a foreign force by disabling its army. Defense will be tightly integrated into the whole region. Even if the foreign force somehow gains control over one coordinating body, or one group, many other local groups will still have the means to defend themselves and the society as a whole. There is no weak central point of authority commanding all defense forces.
There will be no police force with the authority to kill people who don't follow the arbitrary rules set by governments. There will be no such rules, and there will be no such external force that have any right to walk into a community and use violence against its members.
Matters of defense are taken care of locally. That does not in any way mean that people who have a gun have any right to kill or harm other people. Not at all. But they do have a right, as do everybody else, to use their best judgement.
If there is an incident where somebody gets harmed or killed, that particular incident needs to subsequently be examined to determine what went on, who violated who's rights, what were the dynamics of the situation.
If an individual or group was sufficiently physically threatened by another individual or group to warrant a violent response, a subsequent investigation of the facts by a local arbitrating committee might indeed find that this was an appropriate action. Or it might find that it wasn't and might take the action that it deems will best rectify the matter.
There is no law that says you can never kill or harm somebody else. And there is no law that gives anybody any right to kill or harm anybody else. The principal law concerns the balance between the freedom to choose one's own actions and the impermissibility of violating anybody else's freedom to choose. Harming or killing somebody else is a major imposition against their ability to choose. Nobody has any inherent authority to do that. However, if that action is deemed to be in defense of or in deterrence of a major threat to somebody's right to live, that might indeed be found to have been the appropriate action.
In other words, there are no prewritten rules about what specific actions you can or cannot do, or what specifically the punishment would be if you did. But, as part of that, there are no legal technicalities one can use to hide behind if one did something reprehensible. You will have to answer for your actions, no matter if you are a public official, and no matter what rule book you acted out of.
HoloWorld is largely a lively, but friendly place. It is based on principles of non-violence. That is, things are not done by force; subjecting others by force to experiences they don't want to have is not an acceptable thing.
The reason that there is no law saying that violence is illegal is exactly that such a law could only be enforced BY violence. Or, if law enforcement representatives were obliged to follow such a law, then the law breakers could break it without worrying about being apprehended.
HoloWorld, on the other hand, is dedicated to appropriate action; personal responsibility; doing what works in the present situation.