A Marshalltown man’s been arrested, and was arraigned Thursday in federal court in connection with this week’s HAZMAT scare incident at Iowa State University. The U.S. Attorney’s Office spokesman Al Overbaugh says 46-year-old Anand Nariboli was arrested Wednesday night at the apartment where he was living in Marshalltown. Nariboli appeared in court Thursday morning on three charges — threatening to use explosives, making threatening communications, and obstructing use of the mails. There were several letters involved, Overbaugh says. One shut down the Des Moines Post Office on May 19 when it turned out to have rat poison in it. Another was the envelope that spilled white powder this week in a mailroom on the campus of Iowa State University. The man’s also accused of making anonymous calls to a hotline at the state radio dispatch center, making reference to bombs and serial killers. Nobody’s found any bombs. But he threatened to use bombs and blow up an FBI building, in at least one of the messages he sent. It’s not clear how long the threats went on, but Overbaugh says the DCI, police, sheriff’s and federal agencies teamed up to find Nariboli, and agents arrested him on Wednesday night at his Marshalltown apartment. He says they were with the Joint Terrorism Task Force, and the Postal Inspection Service. Overbaugh says other letters were mailed to a Dow Chemical office in Milwaukee, Wisconsin. After Thursday’s appearance in federal court in Des Moines, Nariboli remained in custody. He says he has a detention hearing on Monday, as Overbaugh says right now Nariboli’s being held without bond. Nariboli will have an attorney for his bond hearing Monday when they determine whether he’ll be released, and there’s nobody else charged in this case. In court papers, investigators say Nariboli admitted sending the letters when they arrested him, and provided agents with containers of the powder contained in the letters, which they say were Comet cleanser and D-Con rat poison. He also gave the agents names and addresses of other people to whom he’d sent letters, and the court papers say they were contacted by the investigators.