Frazier Glenn Cross, a 73-year-old man from southwest Missouri with a long history of anti-Semitism, was arrested Sunday afternoon for allegedly opening fire and killing three people – two of them Christian – at and near a Jewish community center in the Kansas City suburb of Overland Park.

As police were taking handcuffed Cross, a resident of Aurora, Mo., and known as F. Glenn Miller, in the back of a car, he yelled out, "Heil Hitler," according to The Kansas City Star.

Matt Davis, who saw Miller's arrest and whose daughter was inside the center when the shooting took place, said that the man was smiling. "I was wondering, 'Why is the guy smiling when he's being arrested.'"

According to the Southern Poverty Law Center, Miller is an Army veteran and retired truck driver who founded the Carolina Knights of the Ku Klux Klan. He has been involved in the "white supremacist" movement for most of his life. He was the group's "grand dragon" until he was sued for operating an illegal paramilitary organization and using intimidation tactics against blacks. Miller then founded a similar group called the White Patriot Party.

In 1987, federal agents found Miller and three other men in an Ozark mobile home filled with hand grenades, automatic weapons and thousands of rounds of ammunition. Miller tried running for U.S. House in 2006 and the U.S. Senate in 2010.

The gunman, who was carrying a shotgun, a handgun and possibly an assault weapon, fired at five people Sunday afternoon but missed two of his targets, according to police.

The shootings, on the eve of the Jewish holiday of Passover, began around 1 p.m. Two males were shot in a parking lot outside the Jewish Community Center of Greater Kansas City, one dying at the scene and the other at a hospital later, according to Reuters. The shooter then drove a mile away to the Village Shalom retirement community and killed a woman.

The shooting came at a time when hundreds of high school singers were expected to audition for a contest.

One of the victims has been identified as William Lewis Corporon, a Johnson County doctor. His 14-year-old grandson, identified as Reat Griffin Underwood, an Eagle Scout, died later at Overland Park Regional Medical Center.

The third victim has yet to be identified.

Corporon and his grandson attended United Methodist Church of the Resurrection in Leawood, a suburb of Kansas City, Mo.

The church's senior pastor, the Rev. Adam Hamilton, told the congregation about the incident during Sunday evening service. "Help us, o Lord, to grieve as people of hope," Hamilton was quoted as praying.

The Jewish Community Center has said it will remain closed Monday. "Our hearts go out to the families who have suffered loss on this tragic day," the center said in a statement. "Our heartfelt gratitude as well to all those in Kansas City and around the world who have expressed sympathy, concern and support."