As usual, the MetaFilter community does a better job a finding links to relevant information and good background articles, so I’ll just link to their thread:

MetaFilter: Police: 50 killed in Florida nightclub terror attack.

Also, on Vox: Why “thoughts and prayers” aren’t enough after a mass shooting.

Read it and spend the seven minutes to watch “America’s gun problem, explained in 18 charts”. I will never understand why “the right to bear arms” trumps huge numbers of gun deaths – most of them suicides, but crime-related deaths and mass shootings as well.

As President Obama said in his statement on June 12, 2016:

“Today marks the most deadly shooting in American history. The shooter was apparently armed with a handgun and a powerful assault rifle. This massacre is therefore a further reminder of how easy it is for someone to get their hands on a weapon that lets them shoot people in a school, or in a house of worship, or a movie theater, or in a nightclub. And we have to decide if that’s the kind of country we want to be. And to actively do nothing is a decision as well.“

(My emphasis.)