No known motive as gunman opens fire near lively entertainment district in Dayton, hours after mass shooting in El Paso, Texas; police say gunman killed by responding officers

Gunman opens fire in crowded shopping center; police say many of the 26 people hurt have life-threatening injuries; suspect arrested without incident

Ex-congressman from El Paso says US president's rhetoric 'fundamentally changes the character of this country and it leads to violence'

Text purportedly written by suspect Patrick Crusius speaks of defending country from 'cultural and ethnic replacement brought on by an invasion'

Authorities say 20 people killed and another 26 wounded in attack at El Paso Walmart; 21-year-old suspect Patrick Crusius in police custody

A look at the most lethal killing sprees in America over the past two years

Police say at least one person in custody, urge public to stay away; local news outlets report several fatalities

Police search home of Santino William Legan, comb social media, in hunt for motive behind deadly attack on Gilroy Garlic Festival

Witnesses report confusion and panic at the Gilroy Garlic Festival, southeast of San Francisco

Judge rules against parents of two victims, who allege school officials failed to follow mandated security protocol and order lockdown that may have saved lives