The FBI is investigating an Omaha man accused of threatening a U.S. Senate candidate in an email.
68-year-old Laurence McCabe sent an email to "End the Gridlock" political action committee that has been running an attack ad on Republican candidate Deb Fischer.
McCabe asked in the email if he had the groups permission to "put bullets in Democrat heads" to end congressional gridlock and suggested Kerrey might be one of those Democrats.
McCabe told an Omaha TV station that he never meant to harm anyone.
The FBI has filed a criminal complaint against him.