A prominent U.S. general has said that in some circumstances it may be appropriate to arm military recruiters.
Andrew Hallinan, who owns a gun store in Florida, said he would would not "arm and train someone who believes the Quran."
"Allowing our National Guard members to carry weapons while on duty gives them the tools they need to serve and protect our citizens."
Investigators were using forensics to determine whether one of the U.S. Marines who was killed used a privately-owned pistol during the shooting.
The church tweeted that God had sent the shooter to Chattanooga on Thursday to kill his victims.
Earlier this year, Mohammod Youssuf Abdulazeez was arrested for driving under influence and also lost a job after he failed a drug test.
The Chattanooga shooter lost his job as an engineer at a nuclear power plant in Ohio in May 2013.
Oklahoma Gov. Mary Fallin, via an executive order, gave the National Guard permission to arm military facilities like recruitment centers.
Louisiana Sens. Bob Corker and Lamar Alexander, along with Gov. Bill Haslam, took part in a memorial service for the Chattanooga victims Friday.
Sen. Ted Cruz said Friday that the U.S. needs to arm its military bases to prevent shootings like Thursday's in Chattanooga, Tennessee, which he called "an act of war."
Federal officials will treat their inquiry into Thursday's deadly Chattanooga shooting as a terror investigation, an FBI spokesman said.
Most people killed by acts of domestic terrorism in the United States are killed by firearms.
The shooting came just about 24 hours after a gunman targeted military offices in Tennessee, killing four Marines.
"He had a big, huge, high-powered rifle," said Gina Mule of Mohammod Youssuf Abdulazeez. "There had to be 20 to 30 shots."
"They were sitting there and they were just targets for this madman," the GOP presidential candidate said on MSNBC's "Morning Joe."
The tight-knit community of Chattanooga, Tennessee, rallied together Friday morning at various vigils to mourn the four U.S. Marines killed during a shooting rampage there a day earlier.
Muhammad Youssef Abdulazeez is believed to be the lone gunman involved in Thursday's shooting that left four Marines dead, according to the FBI.
The shooting on Thursday morning in Chattanooga, Tennessee, had some officials considering more security.
The alleged gunman, who was shot and killed by police in Chattanooga, Tennessee, has been named as Muhammad Youssef Abdulazeez.
Gore's remarks come days before Royal Dutch Shell plans to begin work drilling in the oil-rich Chukchi Sea in the Arctic.
Shootings at two separate locations near Chattanooga, Tennessee, has left four Marines and the suspected gunman dead, according to reports.
Speaking in Tennessee, Tim Tebow calls himself a Christian who just happens to be an athlete.