It still works for a government controlled by the ruling class. The problem is not some malfunction with "police departments" as though a department with a new name could reform it.

"Checks and balances" is and always was a laughably naive and probably intentionally unserious response to overtly structural problems.

What is your serious response to these structural problems then? How do we improve?

Structural problems require structural solutions. A best first step would be reforming the brainwashed American conception of Marxist studies so we can someday conduct a serious discourse concerning the contradictions and consequences of capitalism, which belie the origins and effective purpose of our police departments as we know them.

If anything is for sure, defunding the police was never a remotely serious proposal and it's not lost on Marxists why working people found it such a laughable phrase. Calling it a "proposal" or "strategy" would be giving far too much credit.

In what ways are the existing police services "capitalist"?

All of the police services that I'm familiar with in places like the US, Canada, and Europe lack the fundamental traits of capitalism.

For example, they're the creations of centralized, monopolistic (and often quite socialist) governments, and funded with taxpayer money, rather than arising from the private sector.

As such, there's no competition. Residents and visitors don't get to individually choose which, if any, police service(s) they'll voluntarily receive services from, and what compensation they'll provide, if any. They can't just switch to some other police service if they're dissatisfied with one they've already been choosing to use. They can't unilaterally opt out of dealing with a particular police service.

Entry to the market is also extremely limited. An individual can't just declare himself to be a police officer, and then start offering policing services. An organization of such people can't declare themselves to be a police force.

Unionization of police officers is quite common, as well.

While private security may be available in some areas, it's typically very limited, with no real ability to intervene. They merely monitor an area for trouble, and alert the government's police service(s) if anything arises.

The problems with policing today seem to me to be due to its highly-socialist nature.

Many prisons have been bought up by private companies.

Judges have been convicted of taking bribes in exchange for convictions: https://www.npr.org/2022/08/18/1118108084/michael-conahan-ma...

The first business of the first modern police forces in the US were catching runaway slaves in the south and crushing strikes in the north.

Calling something a "union" doesn't make it socialist. Did you really need me to hold your hand with that?

On what planet are police so-called "socialist"? I suspect this is the brainwashing I was referring to. This kind of nonsense is extremely unique to the United States.

The issue with placing that in the DA's office is they work closely with police on basically all their other cases so they have an incentive to not antagonize the police by actually holding them accountable. The ideal situation is a separate body just charged with dealing with police misconduct so they don't have to worry about police torpedoing their day to day case load in retaliation.

That’s a feature not a bug. Just because they work with the DA doesn’t mean they should be all buddy-buddy.