A mass shooting on Monday at a supermarket in Boulder, Colorado, left 10 people dead, including the first police officer to arrive on the scene, and a suspect injured in the violence was arrested, authorities told a news conference hours later. #News #Reuters #Bouldershooting #Colorado Subscribe: http://smarturl.it/reuterssubscribe Reuters brings you the latest business, finance and breaking news video from around the globe. Our reputation for accuracy and impartiality is unparalleled. Get the latest news on: http://reuters.com/ Follow Reuters on Facebook: https://www.facebook.com/Reuters Follow Reuters on Twitter: https://twitter.com/Reuters Follow Reuters on Instagram: https://www.instagram.com/reuters/?hl=en