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Family members and friends comfort each other as the final roll call is called out during a memorial ceremony, Wednesday, April 9, 2014, at Fort Hood Texas, for those killed there in a shooting last week. (AP Photo/Carolyn Kaster) ( Obama Fort Hoood )

A memorial for Sergeant First Class Daniel Ferguson is seen before a memorial service at Fort Hood on April 9, 2014 in Texas. AFP PHOTO/Brendan SMIALOWSKI/AFP/Getty Images ( 528804542 )

A memorial for Sergeant Timothy Owens is seen before a memorial service at Fort Hood on April 9, 2014 in Texas. AFP PHOTO/Brendan SMIALOWSKI/AFP/Getty Images ( 528804554 )

A memorials Staff Sergeant Carlos Lazaney-Rodriguez is seen before a memorial service at Fort Hood on April 9, 2014 in Texas. AFP PHOTO/Brendan SMIALOWSKI/AFP/Getty Images ( 528804653 )

Soldiers listen to Taps during a memorial service at Fort Hood April 9, 2014 in Texas. US President Barack Obama attended the memorial service for the 3 killed and 16 wounded during last weeks shooting at the post by Army Specialist Ivan Lopez who later took his own life. AFP PHOTO/Brendan SMIALOWSKI/AFP/Getty Images ( 528808213 )

US President Barack Obama speaks during a memorial service at Fort Hood April 9, 2014 in Texas. AFP PHOTO/Brendan SMIALOWSKI/AFP/Getty Images ( 528808331 )

Soldiers prepare for a service where President Barack Obama will attend, Wednesday, April 9, 2014, at Fort Hood, Texas. Last week's shooting rampage left four dead and more than a dozen injured. (AP Photo/Eric Gay) ( Obama Fort Hood )

A military memorial for fallen soldiers is displayed prior to a memorial ceremony for shooting victims that President Barack Obama will attend Wednesday, April 9, 2014, in Fort Hood, Texas. Last week's shooting rampage left four dead and more than a dozen injured. (AP Photo/Eric Gay) ( Obama Fort Hood )

President Barack Obama speaks during a memorial ceremony, Wednesday, April 9, 2014, at Fort Hood, Texas, for those killed there in a shooting last week. (AP Photo/Carolyn Kaster) ( Obama Fort Hoood )

US President Barack Obama pauses while speaking during a memorial service at Fort Hood on April 9, 2014 in Texas. AFP PHOTO/Brendan SMIALOWSKI/AFP/Getty Images ( 528807623 )

President Barack Obama and first lady Michelle Obama arrive for a memorial ceremony, Wednesday, April 9, 2014, at Fort Hood Texas, for those killed there in a shooting last week. (AP Photo/Carolyn Kaster) ( Obama Fort Hoood )

People arrive for a memorial service at Fort Hood April 9, 2014 in Texas. AFP PHOTO/Brendan SMIALOWSKI/AFP/Getty Images ( 528805747 )

US President Barack Obama and First Lady Michelle Obama arrive for a memorial service at Fort Hood April 9, 2014 in Texas. AFP PHOTO/Brendan SMIALOWSKI/AFP/Getty Images ( 528806203 )

US President Barack Obama and First Lady Michelle Obama pay their respects during a memorial service at Fort Hood April 9, 2014 in Texas. AFP PHOTO/Brendan SMIALOWSKI/AFP/Getty Images ( 528808190 )

Memorials for Sergeant First Class Daniel Ferguson (L), Staff Sergeant Carlos Lazaney-Rodriguez (C) and Sergeant Timothy Owens are seen before a memorial service at Fort Hood on April 9, 2014 in Texas. AFP PHOTO/Brendan SMIALOWSKI/AFP/Getty Images ( 528804413 )

US President Barack Obama (2L) and US First Lady Michelle Obama (R) are greeted by Army Lt. General Mark Milley (2R) his wife Hollyanne Milley (L) at Robert Gray Army Airfield on April 9, 2014 in Killeen, Texas. AFP PHOTO/Brendan SMIALOWSKI/AFP/Getty Images ( 528803062 )

A soldier walks past a flag at half staff before a memorial service at Fort Hood on April 9, 2014 in Texas. US President Barack Obama attended a memorial service for the three people killed and 16 wounded during last weeks shooting at the post by Army Specialist Ivan Lopez who later took his own life. AFP PHOTO/Brendan SMIALOWSKI/AFP/Getty Images ( 528804334 )

US President Barack Obama (C) and US first lady Michelle Obama (R) are greeted Army Lt. General Mark Milley, commanding officer of Fort Hood, after arriving at Robert Gray Army Airfield on April 9, 2014 in Killeen, Texas. AFP PHOTO/Brendan SMIALOWSKI/AFP/Getty Images ( 528802924 )

U.S. Army soldiers adjust an American flag before U.S. President Barack Obama speaks at a memorial for victims of last week's shooting on the U.S. Army post at Fort Hood military base on April 9, 2014 in Kileen, Texas. During the shooting rampage on April 2, Army Spc. Ivan Lopez killed three people and wounded 16 others before taking his own life. (Photo by Erich Schlegel/Getty Images) ( 483525153 )