87 percent of school shooters give warning signs and threats, in one way or another.
Joshua Mjoness of North Dakota was arrested after sending messages to his wife threatening a shooting at a Boise, Idaho office.
These measures may include revamping entry policies by installing buzzers or reinforced doors, or maintaining security cameras for better worksite monitoring.
Twenty one Attorneys General asked Congress to expand background checks to include ammunition purchases.
Two Horizon Middle School students in Florida were arrested after police discovered they were allegedly planning a mass shooting at the school.
Jeffrey Clark, who lived with his father, sister and brother, was ultimately picked up on a federal weapons charge that prohibits users of illicit drugs from owning firearms.
Fort Worth police managed to stop suspect with mental health issues as he was attempting to purchase guns.
The high school teacher in Florida found a notebook containing details of who to shoot, where to target on campus, and dates and times that a mass shooting attack should take place.
"Such statements written or uttered WILL NOT be tolerated," school officials said in a message to parents. "School safety above everything else is our NUMBER ONE priority."
The findings also reveal a relationship between media coverage of mass shootings and resulting legislative action.
An impassioned Beto O'Rourke told CNN's Dana Bash Sunday the epidemic of U.S. gun violence is "f***ed up" just one day after the second mass shooting in less than a month in his home state of Texas.
A 25-year-old man sent the texts to an ex-girlfriend. He said schools are "weak targets" and that he preferred a "large crowd of people."
"I don't know why it's taken 251 mass shootings now this year for people to start waking up," Christina Huelsman said.
The El Paso gun store also had twice as many gun sales the week after the Walmart massacre, which did not happen after previous mass shootings in Texas.
Many service-oriented companies have taken notice of the uptick in mass shootings, and they're making sure investors are aware.
"A lot of people in my community feel as though he is a part of the problem," said Andrew Torres, who lost his cousin and her husband in the mass shooting.
"All forms of hate have to really – they have to be reigned in," the Trump official said.
New York congresswoman posted a series of tweets regarding racial disparity in this country.
"I don't know what he's talking about," Dayton Mayor Nan Whaley said as she read Donald Trump's tweets attacking her.
Blaming "intense political polarization," Howard Kurtz pointed out that the trip had been "deemed controversial."
"You and the shooter in El Paso used the same language. Do you regret that?" a reporter asked the president.
"We've lost the traditional values that Republicans have had: free trade, legal immigration and of course fiscal sanity," Nebraska lawmaker John McCollister said.
The president's campaign has posted more than 2,000 ads using the word "invasion" to describe the arrival of migrants and asylum seekers at the southern border since January.
After the mass shooting on Sunday in Dayton, Ohio claimed the lives of nine people and injured 27 others, conspiracy theories online targeted a deceased man bearing the same name as the suspected shooter.
Mayor Nan Whaley said she would communicate to the president during his visit "how unhelpful he's been."
"He laughed. He laughed Marc," Jim Sciutto repeatedly pointed out to Marc Lotter.
Eddie Glaude's speech goes viral online after saying it is too simplistic to place blame Trump for El Paso massacre.
Susan Del Percio slammed the president for showing "absolutely no heart whatsoever" in his address following two weekend mass shootings.
The paper later changed the headline about Trump's mass shootings statement for their second edition.
"Hatred can be concealed by our acceptance of #WhiteNationalism and malice will be revealed in our cashing of NRA checks and failure to act," one Twitter user wrote.