Newark Mayor Cory Booker speaks during a news conference on his plans to campaign for the Democratic nomination to run for the seat of late U.S. Sen. Frank Lautenberg on June 8, 2013 in Newark, New Jersey. (Ramin Talaie/Getty Images)
Cory Booker, the mayor of Newark, N.J., won the Democratic primary for the U.S. Senate.
The Associated Press initially broke the story.
Story is developing; check back for details.