Threatening letters containing suspicious substances sent to Tennessee Republican lawmakers under FBI investigation

Republican state lawmakers in Tennessee received threatening letters containing a suspicious substance Thursday, prompting an investigation by the FBI, officials said.

​CNN.com – RSS Channel Republican state lawmakers in Tennessee received threatening letters containing a suspicious substance Thursday, prompting an investigation by the FBI, officials said. 

​Read More Republican state lawmakers in Tennessee received threatening letters containing a suspicious substance Thursday, prompting an investigation by the FBI, officials said.