A Republican lawmaker's discovery of a magnetic box containing a high-tech tracking device affixed to the bottom of his truck is being investigated by Oklahoma officials, who also revealed that four other GOP legislators have reported concerns they were being followed, according to AP. The mysterious discovery has stunned Oklahoma's political class, and raised questions about who would spy on lawmakers. Oklahoma County District Attorney David Prater described the tactics as "foolish" and potentially criminal. He vowed an aggressive prosecution if evidence suggests someone was trying to intimidate Rep. Mark McBride, who found the device on his truck. McBride says he found the experience "unsettling" and believes it is connected to his legislative work. Prater says four other GOP legislators approached him last year with concerns that they were being followed.