The Capitol Police are investigating a suspicious vehicle north of the Capitol, at New Jersey and Constitution Avenues Northwest, near the Senate office buildings.According to Capitol Police spokeswoman Sgt. Kimberly Schneider, a K9 unit flagged the delivery vehicle as suspicious. Capitol Police are on the scene and are interviewing the driver. No further information is available.“New Jersey Avenue will be closed from Constitution Avenue, NW to D Street, NW. Louisiana Avenue will be closed from Constitution Avenue, NW to D Street, NW until scene clears,— Schneider said in an e-mail.Police on the scene declined to comment.