By Sarah N. Lynch WASHINGTON (Reuters) -The U.S. Justice Department on Wednesday filed federal hate crime charges against an 18-year-old white supremacist accused of killing 10 Black people at a supermarket in Buffalo, New York, last month. Payton Gendron faces 26 counts of hate crimes and firearms offenses, according to a criminal complaint. “We fully recognize the threat that hatred and violent extremism pose to the safety of the American people and American democracy,” said Attorney General Merrick Garland, who traveled to the site of the May 14 mass shooting on Wednesday and met with victi…