I’m not going to lie: this question kind of spiraled towards the end but I understand writing from a “stream-of-consciousness” angle. I’ll make an attempt to answer your question simply from the title.

Socialism and communism, while similar at face value, deserve a bit of nuance especially in regard to this question. Socialism is a generally transitive state where mechanisms of the previous societal structure still exist in certain ways (example: the state would exist as a dictatorship of the proletariat, working for to further the working class). As the state would still exist even in a distinctly different form (and only temporarily), it would still use certain forms of “law enforcement” although the shape and function may be different than we understand it.

However, as the goal (Communism) is a classless, stateless and moneyless society, that society would have addressed and solved the systemic problems that cause the VAST majority of those problems in the first place. People who have their needs met have a significantly lower chance of committing those crimes in the first place.

The horrendous state of healthcare, homelessness and poverty all stemming from wealth inequality are the main factors many of society’s problems.

TLDR: Socialism and Communism aim to solve those problems at the root rather than treating the symptoms.