Charlottesville, Virginia (CNN) It's hard to forget the searing images of a neo-Nazi driving his car into counterprotesters in Charlottesville, Virginia, two years ago today. But if you look at the federal hate crimes report, it's like it never happened at all.

But there can only be guesses at how bad things really are and if they are getting worse.

That's because the FBI's national statistics on hate crimes and annual report are deeply flawed. They are based on voluntary reporting from local agencies with differing definitions of hate crimes and can be riddled with errors.

It makes you wonder what else has been missed, how many other people have been missed?

Mississippi reported just one hate crime for the entirety of 2017 among its 3 million residents across its 82 counties, many with a troubled racial history. Not necessarily because nothing else happened, but because nothing more was reported.

Relying on individual police agencies to have enough resources and good will to report leaves huge holes in the data. And experts say that makes it difficult if not impossible to understand the full scope of hate in America with the ultimate goal of tackling it and even saving lives.

Susan Bro still weeps for her daughter Heyer, who died amid the most high-profile and violent mass gathering of white supremacists in the US in decades. And yet her death was not initially reported as a hate crime to the FBI.

Susan Bro speaks next to a photo of Heather Heyer during a memorial for her daughter in 2017.

"If that's not a hate crime, what is?" Bro says. "It makes you wonder what else has been missed, how many other people have been missed?"

In the absence of a complete set of facts, there is nothing to stop the divisive narrative in America about just how big of a problem racism, hate and hate crimes are, says Heidi Beirich, director of the Intelligence Project at the Southern Poverty Law Center.

Perhaps worse, she says the incomplete FBI statistics relied on for a "national" picture are grossly misleading.

Heidi Beirich studies hate. But without reliable statistics, even she does not know which bias is most prevalent.

"The data that we're collecting is actually belittling the scope of the problem," she says.

"We don't know what the patterns are," she says. "Would it be anti-Semitism that was at the top of the pile? Historically it's been anti-black hate crimes that take the lion's share. Would it be that? I don't know. I just don't know. There's no way to know."

Ex-official suggests some states not even trying

Beirich's frustration is echoed by someone who was in that system. Roy Austin was a former deputy assistant attorney general in the Department of Justice's civil rights division, which deals with hate crimes. In that job, and then as deputy assistant to President Barack Obama for the Office of Urban Affairs, Justice and Opportunity, he knows the frustrations of combating hate all too well.

The current system to track hate crimes is "largely a waste of time" when diagnosing the problem, he says.

Roy Austin, left, appears in Congress during his time with the Obama administration. He remains frustrated at the nation's approach to hate crimes.

"It is completely up to each individual jurisdiction to determine what they provide to the federal government and the federal government accepts those numbers for whatever they are," Austin explains.

Mississippi's single reported hate crime for 2017, the seven in Arkansas and nine in Alabama suggest some jurisdictions "don't even appear to be trying," he says.

Arkansas director of the Crime Information Center, Brad Cazort, pushed back on that.

"It's not because we're not trying," he tells CNN, adding reporting isn't mandatory and the state doesn't have a hate crime law. That could change, though, with Arkansas Gov. Asa Hutchinson saying just last week that he wanted legislation passed.

It's kind of like if I were to tell you all about Egypt, but the only data I had was one pyramid. ... I couldn't explain anything very well. Heidi Beirich, SPLC

Mississippi -- alone among the 50 states -- does not have a centralized crime reporting program, though individual agencies can submit data directly to the FBI. Alabama officials say reporting is not mandatory in their state either, but stress they do provide reminders to law enforcement during the year about reporting hate crimes.

No one doubts there are holes in the data.

"It's kind of like if I were to tell you all about Egypt, but the only data I had was one pyramid. ... I couldn't explain anything very well," Beirich says.

The FBI says 16,149 law enforcement agencies in the country participate in their program. Of those, only 2,040, or less than 13%, reported a total of 7,175 crimes.

That means 87% of the participating agencies reported zero hate crimes in 2017.

A man tends a makeshift candlelight vigil for Heather Heyer and those who were hurt in Charlottesville, Virginia, in August 2017.

"As much as I would like to think that we have fixed the problem, I think that that number is simply false and shouldn't be reported," Austin said.

The FBI acknowledges it is only a clearing house for the facts it is given. And it "continually faces the issue of underreporting at the victim and law enforcement levels," a spokeswoman said. The agency has a "robust training program" for law enforcement officers that explains why reporting this data is so important, she added.

Whether the crimes are not reported by victims or not passed on to the FBI, the result in the national report is the same -- the attacks effectively did not happen.

It's a straight-up 'garbage in, garbage out' problem -- your data is garbage and so you cannot devise strategy based on garbage numbers. Roy Austin, former Department of Justice official

Experts say the need for better data is about ensuring more resources are deployed to areas that could be struggling with hate crimes, as well as understanding trends to better inform governmental policy.

That statistical fog means coming up with a concrete policy as an administration or Congress is difficult, if not impossible, Austin explains.

He suggests the annual FBI report is useless as it currently stands.

"It's a straight-up 'garbage in, garbage out' problem -- your data is garbage and so you cannot devise strategy based on garbage numbers," he says.

Others counter the data is the best we have.

A man walks past memorials in front of the Tree of Life Synagogue after 11 people were shot and killed there in 2018.

While it is "clearly incomplete," the Anti-Defamation League's CEO Jonathan Greenblatt says, it "provides the single best national snapshot of bias-motivated criminal activity" and has been powerful in its ability to increase awareness about hate and confront violent bigotry.

The ADL refers to the FBI reports but also tracks extremist activity from its other sources to get a better picture of the situation.

How major cases slip through the cracks

Heather Heyer is not the only victim of a hate crime whose case is not registered in the annual hate crime report.

A year to the day before she died, Khalid Jabara was shot and killed by a racist man who lived next door, who had repeatedly targeted Jabara and other members of his Lebanese Christian family.

The Jabara family sits with a photo of Khalid. From left: Victoria, Mounha, Haifa, Rami, and his wife, Jenna.

Jabara does not show up in the hate crime statistics for Tulsa, Oklahoma, for 2016, though like Charlottesville, the police do submit hate crime numbers to the FBI.

How both of these hate crime victims were left out of the count shows just one of the glaring problems with the system.

Charlottesville Police Department Chief RaShall Brackney told CNN that part of the issue was that it took the federal government more than a year to categorize the attack as a hate crime.

"Most people do not want to make a mistake and categorize something as a hate crime that cannot be proven as a hate crime," explains Brackney, who took charge ten months after Heyer was killed.

On top of that, Brackney says "a lot of the information that was being uncovered about the suspect was uncovered after the fact."

It was similar for the Tulsa Police Department in Jabara's case: officers struggled with whether the murderer's intention could be proved in court.

Sgt. Shane Tuell says police tried to determine if Jabara was murdered because he had called 911 on his neighbor, because of other circumstances, or because the neighbor "didn't like Lebanese people living next door to him."

But federal standards on submitting hate crime statistics do not require something to be proven beyond a reasonable doubt.

FBI guidance says an incident should be reported as a hate crime when a law enforcement investigation "reveals sufficient evidence to lead a reasonable and prudent person to conclude that the offender's actions were motivated, in whole or in part, by his or her bias."

Jabara's family says they were victims of a years-long torrent of hate from their next-door neighbor who became increasingly violent towards them. They say he would regularly yell: "You filthy Lebanese, get out of here. You filthy Arabs, you Muslims." And they say that he ran over Khalid Jabara's mother, Haifa Jabara, with his car. Police reports of the incident and arrest say the man declared that "Mrs. Jabara and her family were filthy Lebanese and they throw gay people off rooftops" -- an apparent reference to ISIS murders of gay men.

The Jabara family was stunned when they found out, like Susan Bro, that their beloved son and brother Khalid was not counted.

Vicky Jabara with her brothers Rami, center, and Khalid at Rami's wedding.

"I don't know of a clearer-cut case as it relates to hate crime. It was built-up harassment," Khalid's sister Vicky Jabara says.

But still, the incident is not part of the national hate crime record.

"When you look at it statistically, I can see how it would be construed as falling through the cracks," Sgt. Tuell says.

Since CNN started reporting this story, Charlottesville police have sent updated information on the attack that killed Heyer and injured 19 to the FBI. It will not added to the 2017 yearly report that most people access, according to the FBI, because they do not amend those publications. But it should be reflected in a master file, though that file is not currently publicly available.

Demanding change

Tallied or not, the families of Heather Heyer and Khalid Jabara are determined to make their loved ones count in other ways to help future victims.

Flowers, candles and messages surround a photograph of Heather Heyer on the spot where she was killed in August 2017.

A new bill that bears their names in the Senate, and a similar bill in the House, offer funding incentives to departments that report hate crimes.

The Senate bill has high-profile Democrat support from Virginia's two US senators, Mark Warner and Tim Kaine, and presidential candidates Sen. Kirsten Gillibrand and Sen. Kamala Harris. A search is on for a Republican co-sponsor to join them. The companion House of Representatives bill is co-sponsored by a Democrat and a Republican.

The goal is to get a more detailed picture of the state of hate in America so that lawmakers are better informed.

Former Obama official Austin believes that mandatory reporting is the more likely path to more accountability and more attention. If people were to find out that no hate crimes were reported in their city but they had experienced one, they could be more likely to speak out, he says.

"The point of all of this is the preventive. It's not just to know that it happened and to acknowledge it. The point of it is to prevent the next one from happening," Austin says.

It's not clear whether the bill will even be brought for a vote, let alone pass, especially in the current divided political climate.

"We're in a tricky political period," Beirich of the SPLC says, noting that recently there has not been political will from Republicans, especially in a time when "Trump makes light of white nationalism." In scripted remarks, Trump condemned racism and white supremacy following the attacks in El Paso and Dayton.

The domestic terror attack by an alleged white supremacist in El Paso could change political will to act, she adds, but she's not sure. So she hopes for the bill or anything else that will provide more data.

Austin goes further. "You can't have this be voluntarily reported. It has to be mandatory and there has to be some repercussion for not reporting it. And I would start with: you're not eligible for federal cops funding if you don't report your numbers," he says.

Walmart employees pay their respects at a makeshift memorial for the victims of the El Paso massacre.

Austin is frustrated. He's dealt with bad crime data for the last decade. At one point he said police departments did not want to report sexual assault statistics out of fear of what it would do to a city's image. Now the issue is reporting hate data.

Getting Heyer or Jabara into the FBI statistics would be one small step that could perhaps be followed by more.

"I'll take anything that starts moving it in the right direction," Austin says. "I'll take half decent (data) at this point, because what we have right now is really bad."