FBI investigating after suspicious substance found in Pennsylvania ballot envelope

An election worker detected an unidentified substance inside a mail-in ballot envelope in West Chester, Pennsylvania, Friday morning, prompting a brief lockdown and joint FBI investigation, officials said. The worker on the voter services team was organizing ballots at the Chester County government building on Market Street when he noticed a ballot envelope appeared to contain a "non-liquid substance," Chester County District Attorney Christopher de Barrena-Sarobe said during a news conference Friday afternoon. Someone called 911, and a hazardous materials crew responded to the scene. No one was hurt, officials said. "Everything went according to our protocol," de Barrena-Sarobe said.The building shut down but reopened within about 90 minutes when crews determined it was safe.The envelope has not been opened, so the substance has not been identified. The ballot in question has been turned over to the FBI for testing, the DA said.Detectives from the DA's office and the FBI are conductin