Between 5,000 and 7,000 hate crime incidents are reported each year to the FBI. This is how a hate crime is defined and how federal and state authorities prosecute them. (Claritza Jimenez/The Washington Post)

An abaya-wearing Muslim teenager on her way home from a mosque was beaten to death with a metal bat before her body was found dumped in a pond. Her Sunday morning killing is being investigated as an extreme case of road rage —  but not as a hate crime.

A day earlier, three teenagers in Boston were accused of beating a street musician who dressed in a bear costume and played a keytar. They removed the black man’s mask, slammed his face into the ground while yelling racial slurs, then ran off with his money. After the boys were arrested, the district attorney’s office said it is investigating whether they should face hate crime charges.

The legal system’s differing reactions to the attacks on Nabra Hassanen and the unidentified performer near Faneuil Hall spotlight the sometimes fuzzy line between what is a hate crime and what is not.

In general, federal and state hate crime statutes punish people who commit crimes based on a victim’s race, ethnicity, religion or other specified categories.

From there, the laws across the nation can be varied and murky.

[‘Every person deserves to rest in peace’: American Muslims raising money to repair vandalized Jewish cemetery]

For some clarity, The Washington Post spoke with Jack Levin, co-director of Northeastern University’s Brudnick Center on Violence and Conflict, and a sociology and criminology professor who’s published several books on hate crimes.

His answers have been edited for brevity.

What determines whether something is prosecuted as a hate crime?

We have very stringent guidelines about defining what is a hate crime. We have to get into the head of the perpetrator and get at his intentions. And so the evidence in most hate crimes consists of what a defendant says at the crime scene or the graffiti that he may leave there.

So if he voices a racial slur, then it’s much more likely that the offense will be tried as a hate crime regardless of what that offense may be.

Does that legal standard make it harder to prosecute? 

Not all hate mongers are stupid. Many of them do leave evidence at the crime scene, but many others don’t — and so they’re never charged with a hate offense.

There are also plenty of victims who simply will not report hate crimes. They may be immigrants, maybe illegal immigrants who may fear being deported. They may come from some country where the police are part of some tyrannical regime. Or they may be African Americans who historically have had a bad relationship with police going back decades.

What happens to someone who is arrested for a hate crime?

Very few hate crimes are ever prosecuted. (The number of hate crimes committed) is vastly underestimated. But even when someone is arrested, the chances are very slim that it will go to court and that when it does, there will be a conviction based on the hate crime statute.

… For (convicted) adults, it’s almost always an enhancement penalty — tacking on some time in prison during the sentencing phases. But for first offenders, it could be probation with teeth. It could be probation with community service or victim restitution.

Why do states and the federal government have hate crime laws on the books? 

Hate crimes send a message from the perpetrator about the victim and the victim’s group. It’s not just against the primary victim, it’s against everybody in that victim’s group.

… And that’s why hate crimes are important — whether they deter a particular offense or not. It says that Americans do care about the people in that group and welcome them into the community.

Historically, what has precipitated increases in hate crimes in the United States? 

The number of hate crimes escalates as a result of a perceived threat being made by some outside group. A threat to income, culture, religion or even survival.

After 9/11, there was an incredible, dramatic increase in hate crimes against Muslims and Arabs.  … And then in 2003 and 2004, hate crimes against gays and lesbians rose as a result of Massachusetts passing the first gay marriage law. Then after a few months, the number of hate crimes subsided.

And then when Obama was elected the first time, in 2008, hate crimes against African Americans skyrocketed. There were some horrific crimes that were committed by white supremacists across the country.

Every time there’s a threatening incident, it happens. In 2010, hate crimes against Latinos rose. So did the number of immigrants in the country at a time when the unemployment rate was really high.

Critics claim that President Trump’s rhetoric, especially against immigrants, has resulted in an uptick in hate crimes. Can the president have an impact? 

The rhetoric has become a triggering event. It’s socially acceptable now. We used to talk about political correctness in a positive way. Now politically incorrect speech is just being nasty to people. We have a First Amendment and it makes it lawful to be nasty. But there’s a limit.

It’s a shame that more Americans don’t have a grasp of the history. They talk about immigrants who don’t speak English, who live on government handouts. But they forget the same (discrimination) was evident in the 1920s, when Italians and Jews came over. It’s unfortunate that the same people whose ancestors were the victims of hate attacks in other generations now do the same thing.

Read more: 

‘Go back to your country, terrorist’: Man accused of attacking restaurant employee with a pipe

Sikh community asks for hate-crime probe after man is told ‘go back to your own country’ and shot

‘Raw hatred’: Vandals break into interracial couple’s home, spray-paint slurs and swastikas

White supremacist stabs interracial couple after seeing them kiss at bar, police say

‘I was just reading a book’: Canadian cops called on black man reading C.S. Lewis in his car