So if in an ancommunist/ansyndicalist society somebody murders someone for no reason will he be punished...

op's just curious comrade

anarchists are my comrades, sorry if I am misunderstanding how they envision a stateless society working but this is how i see it working in the future

So in anarchy could I threaten to kill you, buy guns and say I will kill you with them, send death threats to you in the mail, make a vlog of myself in a tent behind your house saying I'm going to kill you the next morning with no consequences?

I'd say it depends what the commune democratically decided. Anarchy doesn't mean no rules, but that the rules are not imposed by some hierarchy but decided by the whole community.
As for the enforcement part i'm not entirely sure because i don't know much about anarchy theory. Probably a militia like system, with maybe some workers "specialized" in crime investigation…

but it can have little or no heriarchies involved

This bullshit is exactly why anarchy is a fucking fantasy that could never survive off of paper or outside of Stirner books. It is HIGHLY likely that the people will get a group to watch the roads, to insure that nobody is driving at 300 mph then they will get a group of people to respond to fires, and some people who will respond if there is a shooting taking place. Next thing what do you know there's cops. There's hierarchy.

We'd probably just kill you back and be done with it. Talk shit get hit.

HEY GUYS HOW WILL PEOPLE KNOW TO WIPE THEMSELVES IF THEIR MOMMIES DON'T TELL THEM TO?! :DDDDDDD

Fucking ebin.

No.
Those are not the same thing.

Hell, the police have only existed for about 200 years or so. Before that almost all law-enforcement amongst normal people was done democratically and non-hierarchically, from the age of the greek democracies untill the pricipate in rome got rid of plebian courts, and then it came back after the fall of the Empire.

Your outlook is about as ahistorical as it gets.

fair enough question
i'd imagine anarchy being a gradual decrease in authority and hierarchy of the state where you may not reach perfect anarchy in the foreseeable future, but the goal is to always strive for it
or I could argue that not viewing private property as essential to autonomy gives the community some leeway to punish people for breaking some rules without them directly violating autonomy
for example, the community voted that if you threaten someone online, the community internet not longer works with your individual user id
try to think of some ways a community can punish someone nonviolently
now is denial of common property violence? forced deportation? problems to think about, but not ultimately insurmountable I think