The candidate filing deadline for Southern Arizona's special election in Congressional District 8 is today at 5 p.m.

Four of the seven announced candidates had filed as of day's end Friday. They are Republicans Frank Antenori, Jesse Kelly and David Sitton and Democrat Ron Barber.

That leaves Republicans Mark Koskiniemi, John Lervold and Martha McSally yet to file.

The primary election will be held April 17, with early voting beginning April 2. The two parties' winners will face off in the special general election June 12.

The election was called to fill the seat vacated by Gabrielle Giffords, who said she needs more time to recover from the gunshot wound she suffered to the head at her Jan. 8, 2011 Congress on Your Corner event on Tucson's northwest side. Six people were killed and 12 others, including Barber, were wounded.

The special election will be held within the confines of the congressional district as drawn for the last decade. It encompasses much of Tucson, northern and eastern Pima County, Green Valley, Cochise County and parts of Santa Cruz County. See a map here.

Come this fall, a newly drawn district, Congressional District 2, will replace it when redistricting takes effect in Arizona, including a ninth congressional district in the state.

Several of the candidates running in the CD8 special election have said they plan to be candidates in the CD2 race in the fall.

Return here for full information on the filings after today's 5 p.m. deadline, and hear an in-depth report on the CD8 primary race Tuesday morning at 6:30 and 8:30 on NPR 89.1.