Civil rights lawyers Morris Dees and Joseph Levin founded the Southern Poverty Law Center in 1971. The SPLC is an organization dedicated to exposing and combating radical extremist, hate and bigotry and seeking justice for the most vulnerable citizens in our society. The SPLC works to track and expose the activities of extremist and hate groups.

The recent shootings at two Kansas City-area Jewish centers are being investigated as a hate crime, and this is just the latest example that these extremist groups are not going away anytime soon. Here is a closer look at hate crime in the U.S.:

Hate crime defined

Congress has defined a hate crime as a "criminal offense against a person or property motivated in whole or in part by an offender's bias against a race, religion, disability, ethnic origin or sexual orientation" as reported by the Federal Bureau of Investigation (FBI).

Radical extremists, hate groups and movements are formed by their ideology on or about religion, politics, race, ethnic origins, gender or sexual orientation. Some of these individuals and groups only educate on their beliefs, but others are motivated into action with criminal intent.

Numbers behind the hate

According to the SPLC, an average of 191,000 hate crimes occur per year in the United States. The SPLC reports that there are 939 active hate groups in the U.S. in 2013, which represents a 56 percent increase since 2000.

That growth has jumped sharply in recent years. In 2008, there were 888 hate groups being tracked by the SPLC. In 2012, the number increased to 1,007 hate groups. In just four years, 119 new hate groups formed. The SPLC says this growth in hate groups can be attributed to President Barack Obama's election as well as the current economic and job market conditions.

The threat of these extremist individuals and groups can best be illustrated by the example on the white supremacy movement Stormfront. Stomfront has a white nationalist ideology and was formed in 1995 by former Alabama Klan leader and long-time white supremacist Don Black.

Stormfront was the first major hate website on the Internet, and the group claims 130,000 registered members. The SPLC is reporting that in the last five years, registered members of the Stormfront have committed nearly 100 homicides. The SPLC says Stormfront's website "acts to nurture budding killers and give them moral support."

The SPLC states that the ideology with the most identified hate groups is white supremacy. Other listed hate ideologies noted by the SPLC are anti-immigration, anti-GLBT (gay, lesbian, bisexual and transgender), anti-religious groups and black separatist, as well as anti-government militant groups.

Notable hate crimes in recent years

• In 1998, James Byrd, Jr., an African-American, was murdered by being dragged for three miles behind a pickup truck by three men, of whom at least two were white supremacists, in Jasper, Texas. Lawrence Russell Brewer was executed in Texas 2011 for his involvement in the murder.
• Matthew Shepard, a gay student at the University of the Wyoming, was beaten, tortured and left to die in October 1998 by two men who tied him to a fence, where he wasn't found until the next day. Shepard died five days later from severe head injuries. His assailants received life in prison without parole.
• Daniel Fetty was murdered in 2004 by two men in Waverly, Ohio, who beat him to death with bricks and boards for being gay, hearing-impaired and homeless.
• In 2005, Ronnie Antonio Paris was a 3-year-old boy who lived with his parents in Tampa, Fla. He died due to brain injuries stemming from severe abuse at the hands of his father, who thought the child would turn out to be gay.
• In 2005, Jason Gagewas murdered for being a homosexual in Waterloo, Iowa.
• Naveed Afzal Haq shot six women at the Jewish Federation of Greater Seattle in July 2006, killing one of them. He was sentenced to life without parole in 2009, plus 120 years.
• In 2009, white supremacist and Holocaust denier James Wenneker von Brunn entered the United States Holocaust Memorial Museum in Washington, D.C., in hopes of killing innocent Jews. In the attack, Special Police Officer Stephen Tyrone Johns, 39, was mortally wounded by von Brunn while protecting the lives of innocent museum patrons. Other special police officers returned fired and stopped von Brunn before any other innocent citizen was harmed. Von Brunn died in custody in 2010 while awaiting trial.
• In New Jersey in 2012, a man was arrested and charged with arson for firebombing two synagogues. Anthony Graziano, 19, admitted to police that he started the fire because he hated Jews.
• In 2012, a man who reportedly made anti-gay slurs about his transgendered girlfriend in a New York City McDonald's attacked 24-year-old Jamar McLeod. The restaurant's surveillance cameras recorded the incident.
• Wade Michael Page, who had ties to white supremacist organizations, shot and killed six people at a Sikh temple in Oak Creek, Wis., and wounded four others in August 2012, He then committed suicide. Attorney General Eric Holder called it "an act of terrorism, an act of hatred, a hate crime."
• In 2013, Lashawn Marten, was charged with manslaughter as a hate crime for the deadly Union Square Park attack on a 61-year-old white man after police stated Marten wanted to "punch the first white man" he saw. Police say this was a racially-motivated attack.
• In 2014, in Kansas City, Mo., Frazier Glenn Miller, a former "Grand Dragon" of the Carolina Knights of the Ku Klux Klan killed three people at the Jewish Community Center of Greater Kansas City and at the Village Shalom Retirement Center. Miller will face hate crime charges associated with these homicides.