Buford schools were on voluntary lockdown Tuesday as authorities searched for a Buford man suspected of threatening to kill his mother, her animals and any police officers if she called 911. The search began Tuesday morning when 24-year-old Dustin York’s mother called authorities to report that her son, who had threatened her Monday night, may be in the woods behind her home, according to Gwinnett County police. Officers arrived after the mother called and spotted York, who is wanted on aggravated assault and false imprisonment charges.