Carlos Moreno, 66, was shopping with his wife and daughter at a Walmart Supercenter in Thornton, Colorado, on the evening of November 1, 2017, when a gunman opened fire inside the store. Moreno, described by family as a joyful, caring man who moved to Thornton in 1998 and was born in San Antonio, Texas, was killed at the scene along with 26-year-old Victor Vasquez. A third victim, 52-year-old Pamela Marques, was taken to hospital and later died. The attack sent shoppers fleeing amid mass chaos.

Investigators identified the suspect through surveillance footage from about 200 cameras in and around the store and arrested 47-year-old Scott Allen Ostrem the next day in Westminster after a public tip. Reports say Ostrem had abruptly left his job hours before the shooting and that family members noted longstanding mental health problems. The motive remains unknown.

Did anyone who shopped at that Walmart on November 1, 2017, see or hear anything that could help clarify what happened?