People visit a makeshift memorial honoring the victims of the Oct. 1, 2017, mass shooting in Las Vegas, on Nov. 12, 2017. Five years after a gunman killed 58 people and wounded hundreds more at a country music festival in Las Vegas, in the deadliest mass shooting in modern U.S. history, the massacre is now part of a horrifying increase in the number of mass slayings with more than 20 victims, according to a database of mass killings maintained by The Associated Press, USA Today and Northeastern University. (AP Photo/John Locher, File)