Netflix's Making a Murderer has, for many, led to just one question: Is Steven Avery innocent? This has been the focus of the discussion surrounding the documentary series, which follows a Manitowoc County, Wisconsin, man who was wrongly convicted of an attempted murder and rape he didn't commit, exonerated after 18 years, and then tried for another crime — a murder — and sentenced to life in prison.

But the focus on Avery's guilt or innocence misses what the docu-series really achieves: It exposes the American criminal justice system's biggest weakness. For all the surprise and talk about Avery's case as an individual, extreme case, the series shows what are systemic problems in the US justice system — particularly, the system's total lack of accountability.

In Avery's case, there are plenty of areas where red flags should have led the process to pause — but didn't. Avery's previous false conviction for crimes he didn't commit and the evidence that police and prosecutors neglected in that case. The police and prosecution's insistence on going after Avery and his nephew, Brendan Dassey, for the murder of Teresa Halbach. The questionable — and perhaps planted — evidence. The seemingly coerced, potentially false confession from Dassey. (More on all of this here.)

As noted in Making a Murderer, even the state watchdog group for local police agencies concluded that there had been no wrongdoing for Avery's prior false conviction. A man was wrongly sentenced to 18 years in prison, and the official conclusion was that everything was fine.

Yet somehow, this isn't too surprising. Time and time again, I've seen similar cases around the country, in which people face wrongful convictions or smaller abuses at a truly endemic level. Often, it's rare anyone is there to prevent or stop the abuse and neglect that allows these types of cases to happen — at least until someone spends decades, or perhaps his or her entire life, in prison.

Abuse and neglect are frighteningly common in the criminal justice system

To whatever degree the criminal justice system is accountable or encouraged to do anything, it is pushed in the direction of being tough on crime. This means, as it did in the Avery cases, pushing toward proving someone is guilty of a crime and then convicting them for it, even if there's reasonable doubt that the defendant is not, in fact, guilty.

Here are just a few examples from the past several years, taken from the 125 total exonerations by courts in 2014:

Glenn Ford of Louisiana was wrongly sentenced to death row for 30 years for a murder he didn't commit before he was finally exonerated. There was always evidence that could have acquitted Ford, but officials ignored it during trial. Marty Stroud, the prosecutor in Ford's case, even admitted as much in a letter to the local newspaper: "In 1984, I was 33 years old. I was arrogant, judgmental, narcissistic and very full of myself. I was not as interested in justice as I was in winning." Daniel Larsen of California was wrongly convicted of possessing a concealed weapon in 1999, serving nearly 15 years of a 28-years-to-life sentence before he was exonerated. Police claimed they saw Larsen throw a knife after receiving a 911 call about a fight in a parking lot, even though he didn't fit the description given by the 911 caller. Then a cop changed his testimony to make the charge stick. Finally, Larsen's trial lawyer — who was later disbarred — failed to investigate the case before trial and overlooked evidence that may have helped him. Michelle Murphy of Oklahoma was wrongly convicted of killing her 15-week-old son in 1995. A detective, who had been involved in a false confession in another case, extracted a false confession from Murphy. A forensic analyst also wrongly testified that Type AB blood found at the scene couldn't rule out Murphy as the culprit, even though she is Type A and her baby was Type O. Before her exoneration, she served nearly 20 years, and her daughter was put up for adoption while she was in prison.

Again, these are only three of the 125 exonerations handed out in 2014, out of nearly 1.6 million prisoners in the US that year. But you could pull out any of these 125 cases and find some outrageous facts — the criminal justice system doesn't give a wrongful conviction unless something goes wrong along the way, after all.

Still, consistent themes run through these cases: A horrific crime, police and prosecutors eager to get a conviction so they can say they solved a crime, and a system that didn't hold law enforcement officials accountable, or put proper checks on them, to prevent a wrongful conviction that led to sometimes decades in prison.

Chances are, too, that the record 125 exonerations in 2014 represent only a fraction of the innocent people in prison that year. Advocates, after all, say the exoneration count is going up not because the justice system is getting worse but because technology, like the internet, has made it easier to shine a light on wrongful convictions.

The law enforcement officials in these cases were not necessarily evil or corrupt. They likely thought they had the right culprits. But police and prosecutors, as in Ford and Larsen's cases, were pushed to pursue a conviction, even if it meant ignoring evidence or changing a statement. The system, after all, rewards police officers and prosecutors for locking up supposedly bad people, not for doing a proper investigation and letting the wrongly accused go free.

Police and prosecutors were pushed to pursue a conviction, even if it meant ignoring evidence or changing a statement

Looking back at Avery's case, Making a Murderer suggests that the Manitowoc County Sheriff's Office and prosecutors went after Avery for the murder of Teresa Halbach, which landed him in prison in 2007, because of a personal vendetta — rooted in the embarrassment they faced after Avery was exonerated of the previous rape and attempted murder.

But there's another explanation: After Halbach's murder gained public attention, both police and prosecutors realized they needed to prove to media and the public they could solve this case. So when the evidence pointed to Avery, they went after him in full force to show they were tough on crime. Even if cops planted evidence, as Making a Murderer suggests, this could have been out of the genuine belief that they had the right guy — and wanted to guarantee they landed a conviction the public so desired.

This is not to detract from wrongdoing and abuse perpetuated by individuals in these cases. Obviously, they're culpable for their own bad behavior. The point, instead, is to shine light on how the criminal justice system pushes people to act badly — and does little to hold them accountable when they mess up.

No one holds most of the justice system accountable

Ultimately, the fundamental problem in all of these cases is there's no solid measure of accountability in the justice system.

For one, the system that deals with the most scrutiny from lawmakers, the media, and the public — the federal system — is actually a small fraction of the overall US justice system. Federal prisoners made up just 13 percent of all US inmates in 2014, according to the Bureau of Justice Statistics. But barring a major scandal or police shooting, it's the federal system that tends to get a lot of attention.

"The local level operates below the radar," John Pfaff, a professor at the Fordham University School of Law, said, pointing to the role of enormously powerful local prosecutors. "No one has any oversight for them, outside of the four states where [prosecutors] are appointed. There's no one to step in and say, 'You're doing a bad job, you're fired.' Unless voters decide to step in and vote this person out, there's very little accountability."

"There's no one to step in and say [to most local prosecutors], 'You're doing a bad job, you're fired'"

Pfaff argued that people tend to underestimate the importance of the local system. For example, more than 530,000 people have signed two petitions asking President Barack Obama to pardon Avery — even though Obama's pardon powers are limited to federal crimes, and Avery is a state convict. It seems like a case of people assuming the federal system holds all the power when, in fact, the local and state systems do.

There are supposed to be some checks on the criminal justice at all levels, from the smallest town's jail to the biggest federal penitentiary. But often, these just aren't sufficient to catch even some of the major abuses by law enforcement.

The first safeguard to an overzealous police department or prosecutor, for example, is supposed to be a person's right to an attorney. But in the US, it's safe to describe legal representation as a two-tier system: Someone either hires an attorney with plenty of expertise and a big staff, or he or she gets a public defender who is often overworked and underresourced.

A 2009 study by the National Association of Criminal Defense Lawyers, for example, found that part-time public defenders in New Orleans are effectively limited to seven minutes per case on average for all types of cases. This isn't enough time to provide an adequate defense to the thousands of clients they receive. (Making a Murderer reveals the hit-or-miss nature of public or appointed legal counsel: Dassey's publicly appointed attorneys were, overall, much worse than Avery's privately hired attorneys; the documentary series even showed evidence that one of Dassey's attorneys seemed to conspire against him.)

The courts, too, are supposed to enforce some accountability, but often they have the incentive to lean on a guilty verdict. For example, in most states, judges are elected, typically under tough-on-crime messages. This puts pressure on them to ensure that someone who could be — not necessarily is — a dangerous criminal is locked up for a long time. After all, if that person is freed and goes on to commit another crime, the judge would be one of the first people blamed.

Part-time public defenders in New Orleans are effectively limited to seven minutes per case on average

This is not a theoretical: In previous cases, parole and pardon decisions have led to an ex-offender getting out of prison and committing another crime, leading to public outrage. In Massachusetts, for instance, the parole board released a man who went on to kill a cop during an armed robbery in 2010. These types of cases create fear all across the justice system, making the default action to keep people in prison or jail, regardless of whether they are a threat to the public.

Another level of oversight comes from state and federal watchdog agencies that are supposed to investigate abuse and misconduct in lower-level law enforcement. Often, however, the agencies are horribly understaffed, and they couldn't possibly address all the mistakes that go on in the system. As Jonathan Smith, a law professor at the University of the District of Columbia, told the Huffington Post, "It's important for the [US Department of Justice's Civil Rights Division], with limited resources, to make decisions that are strategic and not only just go to where it's bad, because there's a lot of places in this country where policing is bad and where intervention is necessary."

What about the media? It can expose some cases — Netflix, for one, gave a very big audience to Avery's case. But tens of millions of cases go through the US court system each year. The media can't possibly go through all of these cases and hold every single action by law enforcement accountable.

The final say may in fact fall on voters. But even the electoral system seems to fail to hold local officials accountable for problems. Consider prosecutors, who decide what charges — and therefore potential punishment — people face, whether people face charges at all, and, typically, the terms of a plea agreement if a defendant wants to avoid trial.

Yet when it's time to hold prosecutors accountable, voters by and large don't turn out, don't have a choice, or vote for the incumbent. In nearly 1,000 elections between 1996 and 2006 analyzed by Ronald Wright at the Wake Forest University School of Law, 95 percent of incumbent prosecutors won reelection and 85 percent ran unopposed in general elections.

"The public cares about prosecutors' conviction rates. It's about winning the trial."

If prosecutors do face any pressure, it's usually to be tough on crime — meaning lock up as many people as possible. Moira Demos, one of the creators of Making a Murderer, noted this flaw in the system in an interview with Vox's Todd VanDerWerff: "The public cares about prosecutors' conviction rates. It's about winning the trial." But this effectively encourages prosecutors to land a conviction no matter what — even if the facts of a case may change, as occurred in some of the exoneration cases noted above.

The result of all these gaps: Much of the criminal justice system faces little to no oversight, and the incentives that do exist encourage officials to convict as many criminals as possible, not necessarily get to the truth of a situation.

Now, it's not realistic to expect that every mistake in the American justice system be caught. The US is a very big country with a fragmented criminal justice system, and mistakes will happen. But as it stands, the system is built to make mistakes, despite sometimes huge indicators that something is wrong.

How can this change?

There is no easy answer to fixing this mess, but there are some ideas.

For one, voters could take law enforcement elections more seriously. Prosecutors, for instance, are tremendously powerful — Pfaff's study found that prosecutors drove mass incarceration in the 1990s and 2000s by filing more charges even as arrests fell. Yet, as shown in Ronald Wright's research, voters rarely hold prosecutors accountable.

"It's an unsatisfying solution," Pfaff said. "We're all looking for that one big law or regulatory fix we can do. I don't think that's going to be where the answer comes from. I think it's going to come from more of a long, slow slog and cultural shift."

Steps could be taken to reasonably limit law enforcement. Going back to prosecutors (who are tremendously important at the local level), states could issue guidelines that try to narrow prosecutors' actions under specific circumstances. Laws could also be changed to give some officials less discretion.

"I think [change is] going to come from more of a long, slow slog and cultural shift"

"Legislators could streamline the criminal codes a lot," Pfaff said. "Some states can have 20 to 25 assault provisions, which gives [prosecutors] tremendous authority to stack multiple charges, pick and choose who they're going to get and what for, etc."

There could also be better efforts to collect data on what local police and prosecutors are doing. This could be costly, particularly in rural areas that still work largely with pen and paper, but it would help the media and researchers better gauge what these lower-level systems are doing — something that's frankly impossible in many places today without on-the-ground work.

Fortunately, there are some positive developments in this area. In the past few years, local, state, and federal lawmakers of both political parties have moved to reform the system to ease mass incarceration. The US public, too, has embraced a softer approach to criminal justice — the attention going to Making a Murder captures some of that mood, but polls also show that Americans would like to peel back, for instance, harsh mandatory minimum prison sentences for drugs.

But the system is still largely broken — so much so that when something goes wrong, it's not really surprising no one is held accountable for it. Until that changes, America should expect more cases similar to, although perhaps not as extreme as, Avery's.

Watch: How mandatory minimums helped drive mass incarceration