A chef working at a large hotel chain in Long Beach, California, planned a mass shooting aimed at colleagues and guests when he must have been unhappy with his employer. A 15-year-old girl in Fresno, California, posted a photo on a gun case along with the text "Don't come to school tomorrow". In Seattle, Washington, a 35-year-old man was arrested after threatening to kill people and "exterminate Latin Americans."

In total, CNN lists 27 cases where people have been arrested after pronouncing mass shootings, the weeks after a total of 31 people were killed in less than a day in El Paso, Texas and Dayton, Ohio

"A responsibility to investigate"

Five of the threats involved school shootings. Others had racist, anti-Semitic and homophobic motives.

At least one of the arrested has said he was not serious about his threat.

- Law enforcement agencies have a responsibility to investigate and answer those who choose to make this type of threatening statements, following the mass violence we have seen in Florida and across the country, a sheriff involved in one of the cases writes on Facebook, according to CNN.

After the shooting in El Paso and Dayton, the FBI said it was worried that violent extremists in the United States would be inspired by the attacks.