WASHINGTON  - A shotgun-wielding man opened fire at two Jewish sites in suburban Kansas City on Sunday, killing three people - including a teenager and his grandfather - and shocking a peaceful community.

Police arrested Frazier Glenn Cross, 73, of Aurora, Missouri, and booked him into the Johnson County, Kansas, jail Sunday evening, charging him with premeditated murder, according to the police report.

According to the Southern Poverty Law Center, Cross - whose real name is Frazier Glenn Miller - is a former “grand dragon” of the Ku Klux Klan with a long history of running illegal paramilitary organizations and intimidating minorities.

The shootings occurred at the Jewish Community Center of Greater Kansas City, which is in Overland Park, and at Village Shalom, a retirement home nearby, Overland Park Police Chief John Douglass said at a news conference.

“We’re investigating it as a hate crime. We’re investigating it as a murder,” said Douglass, flanked by a representative of the Kansas City FBI office and prosecutors.

The shootings also occurred the on the eve of Passover, a holiday significant in Judaism.

President Barack Obama called the shootings “horrific” and said he was staying in close contact with federal, state and local law enforcement officials to provide additional resources, if needed. “While we do not know all of the details surrounding today’s shooting, the initial reports are heartbreaking,” he said in a statement.