A woman who said she works at the Washington Navy Yard looks at a memorial to the shooting victims on Wednesday, September 18. Authorities said 12 people -- plus the gunman -- were killed in the shooting on Monday, September 16. <a href="http://www.cnn.com/2013/09/16/us/gallery/navy-yard-shooting/index.html">View photos from the scene of the rampage.</a>
Nation mourns Navy Yard shooting victims —
A woman who said she works at the Washington Navy Yard looks at a memorial to the shooting victims on Wednesday, September 18. Authorities said 12 people -- plus the gunman -- were killed in the shooting on Monday, September 16. View photos from the scene of the rampage.
AP Photo/Jacquelyn Martin
A handwritten note is taped to a post across the street from the Washington Navy Yard on September 18.
Nation mourns Navy Yard shooting victims —
A handwritten note is taped to a post across the street from the Washington Navy Yard on September 18.
AP Photo/Jacquelyn Martin
A man puts a bouquet at the anchor outside the Washington Navy Yard on Tuesday, September 17.
Nation mourns Navy Yard shooting victims —
A man puts a bouquet at the anchor outside the Washington Navy Yard on Tuesday, September 17.
Jacquelyn Martin/AP
A flag flies at half-staff behind Valerie Parlave of the FBI and Washington Police Chief Cathy Lanier during a press conference on September 17 outside the FBI's field office in Washington.
Nation mourns Navy Yard shooting victims —
A flag flies at half-staff behind Valerie Parlave of the FBI and Washington Police Chief Cathy Lanier during a press conference on September 17 outside the FBI's field office in Washington.
JIM LO SCALZO/EPA/Landov
Defense Secretary Chuck Hagel, right, and Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, second from right, present a wreath at the Navy Memorial in Washington on September 17.
Nation mourns Navy Yard shooting victims —
Defense Secretary Chuck Hagel, right, and Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, second from right, present a wreath at the Navy Memorial in Washington on September 17.
J. Scott Applewhite/AP
Washington Nationals relief pitcher Ian Krol wears a Navy hat in the dugout of Nationals Park in Washington before a game against the Atlanta Braves on September 17.
Nation mourns Navy Yard shooting victims —
Washington Nationals relief pitcher Ian Krol wears a Navy hat in the dugout of Nationals Park in Washington before a game against the Atlanta Braves on September 17.
Alex Brandon/AP
The Washington Nationals have a moment of silence for the shooting victims before their game on September 17.
Nation mourns Navy Yard shooting victims —
The Washington Nationals have a moment of silence for the shooting victims before their game on September 17.
Patrick Smith/Getty Images
U.S. flags surrounding the Washington Monument fly at half-staff on September 17.
Nation mourns Navy Yard shooting victims —
U.S. flags surrounding the Washington Monument fly at half-staff on September 17.
J. Scott Applewhite/AP
From left, Brittany Carter, Jibri Johnson and Bryan Beard attend a small candlelight vigil at Freedom Plaza in Washington on September 16.
Nation mourns Navy Yard shooting victims —
From left, Brittany Carter, Jibri Johnson and Bryan Beard attend a small candlelight vigil at Freedom Plaza in Washington on September 16.
Andrew Harnik/The Washington Times/Landov
Brittany Carter wipes tears away at the September 16 vigil.
Nation mourns Navy Yard shooting victims —
Brittany Carter wipes tears away at the September 16 vigil.
Andrew Harnik/The Washington Times/Landov
Dave Gray and his wife, Brittany, of Salt Lake City hold candles in remembrance of people affected by gun violence.
Nation mourns Navy Yard shooting victims —
Dave Gray and his wife, Brittany, of Salt Lake City hold candles in remembrance of people affected by gun violence.
Greg Kahn/Getty Images
The U.S. flag above the Treasury Department flies at half-staff on September 16.
Nation mourns Navy Yard shooting victims —
The U.S. flag above the Treasury Department flies at half-staff on September 16.
Andrew Harnik/The Washington Times/Landov
Gordon Morris, left, and wife Laura watch as flags are lowered to half-staff during the September 16 vigil at Freedom Plaza.
Nation mourns Navy Yard shooting victims —
Gordon Morris, left, and wife Laura watch as flags are lowered to half-staff during the September 16 vigil at Freedom Plaza.
Greg Kahn/Getty Images
Eddie Weingart of Project End Gun Violence speaks to the media on September 16.
Nation mourns Navy Yard shooting victims —
Eddie Weingart of Project End Gun Violence speaks to the media on September 16.
Greg Kahn/Getty Images
Members of the media cover the vigil on September 16.
Nation mourns Navy Yard shooting victims —
Members of the media cover the vigil on September 16.
Andrew Harnik/The Washington Times/Landov
The U.S. flag flies at half-staff above the White House the day of the deadly shooting.
Nation mourns Navy Yard shooting victims —
The U.S. flag flies at half-staff above the White House the day of the deadly shooting.
Evan Vucci/AP
The Rev. Andrew Royals offers communion to Vinh Tran during a Catholic Mass at the St. Vincent De Paul Church on September 16. A prayer for the shooting victims was held at the church, which is just blocks away from the site of the violence.
Nation mourns Navy Yard shooting victims —
The Rev. Andrew Royals offers communion to Vinh Tran during a Catholic Mass at the St. Vincent De Paul Church on September 16. A prayer for the shooting victims was held at the church, which is just blocks away from the site of the violence.
Melina Mara/The Washington Post via Getty Images