In the weeks following mass shootings in Texas and Ohio, more than two dozen people across the country have been accused of making similar threats.

A hotel cook in Long Beach, California has joined the list of people arrested over threats to commit mass shootings. The FBI has been working nonstop to stop copycat attacks and identify threats.

"Suspect had clear plans, intent, and the means to carry out an act of violence that may have resulted in a mass-casualty incident," says Long Beach Police Chief Robert Luna.

Democratic candidates hit a familiar theme of gun control on the campaign trail Thursday.

"Change doesn't come from Washington, it comes to Washington from people who are demanding it," said Sen. Cory Booker.

Even in Texas, a red state, Gov. Greg Abbott created the Texas Safety Commission to discuss the root causes of domestic terrorism, among other goals.

Meanwhile, Walmart announced a permanent memorial at the scene of the shooting in El Paso. Last week, its CEO said he supports common-sense gun control policies, but stopped short of pulling guns off the shelves.