CHICAGO – A 21-year FBI veteran with experience investigating terrorism, organized crime and drug-trafficking cases has been named as the new head of the agency's high-profile Chicago office, the FBI announced Wednesday

Cory B. Nelson will oversee an office that has taken a lead role in prominent investigations in recent years, including the corruption case of now-imprisoned former Illinois Gov. Rod Blagojevich and multiple terrorism cases.

Nelson replaces Robert Grant, who retired in September after more than seven years as the special agent in charge of the Chicago office. Grant left to take a global-security position with Walt Disney Co. in Los Angeles.