Suspect in British MP Jo Cox Slaying a Longtime Neo-Nazi Supporter, Watchdog Group Says

— -- The man suspected of killing British lawmaker Jo Cox was a longtime supporter of a U.S.-based. neo-Nazi organization, according to a watchdog group that tracks extremists.

Cox, a British Member of Parliament (MP) and mother of two, was killed in a shooting and stabbing midday Thursday after a town hall meeting in West Yorkshire, England.

She was an MP for the Labour Party. Cox, 41, was campaigning for the United Kingdom to remain in the European Union and was known for her work on Syria-related issues. She reportedly had been subjected to hate mail and police were poised to put extra security in place for her.

According to records obtained by the Southern Poverty Law Center, the U.S.-based organization that monitors hate groups, the suspect, whom the center identified as Thomas Mair, was a “dedicated supporter” of the National Alliance, a once-prominent white supremacist organization in the United States.

He purchased a manual from the National Alliance that included instructions on how to build a pistol, the center said.

The man sent a total of $620 to the group’s publishing imprint to purchase works including “Chemistry of Powder & Explosives,” “Incendiaries,” “Improvised Munitions Handbook” and “Ich Kampfe,” which was published by Adolf Hitler’s Nazi political party, the center said.

Mair was charged with murder and weapons possession, West Yorkshire police said Friday night. They were not looking for anyone else and Mair's motives remain unknown.

Cox’s death has brought an abrupt halt to the campaign for next week's referendum on the U.K.'s membership in the European Union, or the so-called Brexit. People from around the world and across the political spectrum paid tribute to the slain politician this week.

Police search teams arrived this morning at the scene in the town of Birstall, where the investigation continues.