The residents and authorities in a Dallas suburb on Sunday began to process the shooting at a crowded mall in which the police say a gunman killed at least eight people, including children, and injured at least seven others before a police officer killed him. Volunteers erected a memorial and placed flowers outside the entrance to Allen Premium Outlets, where the shooting occurred on Saturday. The 33-year-old gunman was armed with what officials said was an AR-15-style rifle. The killings came just over a week after a mass shooting in rural San Jacinto County, north of Houston, where five people living together were killed by a neighbor after they asked him to stop shooting his gun in his front yard. And they occurred a little less than a year after the massacre at Uvalde, where two teachers also died. In the past two years, as Texas has been shaken by more than a dozen mass killings of four or more people, the state has increased access to firearms, doing away with its permit requir...