Sometimes, you don’t do what you advocate, because you can’t.
Consider the following example: crime in Baltimore City. Consider further the obstacles to investigating and apprehending/neutralizing offenders, outside of joining the police force (which has other issues):
- Practically speaking, with how Baltimore police enforce, you can’t have any gun. Not only will they search and imprison you for simple possession, they (and many other jurisdictions) have free license to shoot you if you talk about a gun, or if they can see it anywhere on your person, regardless of threat or disposition.
- Maryland Criminal Code Title 4 Subtitle 1 Section 4-101 contains language like “(2) A person may not wear or carry a dangerous weapon, chemical mace, pepper mace, or a tear gas device openly with the intent or purpose of injuring an individual in an unlawful manner.” Given that unlawful manner often winds up being “whatever the police officer you ran across at the time thought”, and furthermore that vigilante behavior in general is frowned upon, it’s quite dubious whether you are going to be able to have pepper spray when attempting any civilian law enforcement or investigation.
- Body armor is legal to wear, but only if the Police Commissioner of Baltimore pre-approves after what amounts to a background check. (Police Ordinance 3-4)
- Tasers/stun guns can’t be carried in government buildings, including public schools, in addition to personal history restrictions. (Police Ordinance 59-48)
- Under Maryland Courts and Judicial Proceedings Section 10-401 and succeeding, it is at minimum questionable, and probably illegal, for a civilian to make audio recordings such as those captured by body cameras. As for practice, perhaps recording public communications such as street encounters are legal, but you also see police officers denying, confiscating, or demanding deletion of footage. (Note: this garbage statute has the usual non-intuitive uses of language, but even if you try to sort through the abusive definitions, it is not at all clear what the boundaries are.)
Notice the sum total of the above, as it relates to what we would consider the common kit and procedure for a patrol officer. Some of it is doable; some of it is questionable; some of it is outright or practically banned; even doing the equivalent of body cameras is risky. So if we are trying to avoid conflict with the government authorities, we already can’t do best practices, and in some cases would have to take reckless risks.
Consider also the question of how you detain or punish the offenders. We would not want people detaining people without evidence, trials, and other due process. To get those things done, it’s not just that you need a system of judges or juries: you also need somewhere to put these people, that is reasonably safe for everyone, and which has the appropriate level of staffing, not just for inmate sustenance, but to avoid prison attacks and escapes. That’s a major financial outlay, especially when you consider the winter season requires indoor storage.
Likewise, you do not want people storming into other people’s houses wearing street clothes. In order to avoid armed confrontations, you need to have an overall situation where people rarely are kidnapped by armed attackers, and where when law enforcement has to force their way in, that the officers are identifiable, so a person can make the correct decision to put down the guns and retreat. If you have small bands of people attempting to enforce the law in a large city, you are going to have far more of these high-risk confrontations.
So then we would return to the larger question: let us say that you believe there should be more law enforcement, but you haven’t been able to persuade others to provide more funding. Can you go out into the streets, functionally to evidence the strength of your belief? In this case, no, not really. If you are inserting yourself into the middle of gangs that kill with a high percentage of impunity, that’s far too close to suicide vs. constructive action.
You can construct for yourself the similar reasoning, for example with regards to education of children. If the state mandates particular methods, facilities, and processes, if you wish to avoid direct conflict, you can’t do something different, except through (influence) political processes that may be ineffective.
You also have the case where the job is simply too big for you to handle with your own economic resources, even if you put everything into it.