The Saudi who killed three at a Florida Navy installation was inspired by jihadist ideology, the U.S. attorney general said.
Saudi trainees were found to have connections to extremist movements or be in possession of child pornography.
Investigators have been trying to access the two devices — an iPhone 7 and an iPhone 5 that belonged to Mohammed Alshamrani.
Acting Navy Secretary Thomas Modly said the service must learn from the recent attacks at three federal installations.
Roughly 400 people gathered at a Savannah church to remember 21-year-old Airman Apprentice Cameron Scott Walters.
The letter comes after Saudi national Mohammed Saeed Alshamrani opened fire in a classroom on December 6.
The screening apparently failed to turn up Alshamrani's exposure to jihadist ideology before coming to the U.S.
Navy leaders called the move "right and fitting."
About a dozen Saudi students who were acquaintances of the shooter are currently confined to the base.
About a "dozen or so" Saudi nationals are under the control of the FBI amid an ongoing investigation, DefSec Esper said.
The open letter, published Thursday morning by National Security Leaders for Biden, contains 489 names.
Families of those lost in the USS Thresher tragedy are finally getting a look at hundreds of documents about the accident.
The campaign of President Donald Trump released a letter from 235 retired senior officers backing his re-election.
The America Class amphibious assault ship was virtually commissioned July 15 at its shipyard in Pascagoula, Miss.
Three Marines and a sailor have been bitten by a coyote on the loose at Camp Lejeune.