ST. LOUIS PARK, Minn. (AP) — The shooter who killed two schoolchildren and injured 21 other people at a Catholic church in Minneapolis visited a suburban gun shop the weekend before the attack, but the owner of the store said Thursday that his staff saw no warning signs in their interactions.Gun store owner Kory Krause told The Associated Press that Robin Westman spent around 40 minutes at Frontiersman Sports in St. Louis Park on Aug. 23 and appeared completely at ease. A surveillance video showed Westman examined several guns before ultimately buying a revolver.Westman had already passed the required background checks and had a valid permit to purchase the gun, Krause said.AdvertisementAdvertisementAdvertisementAdvertisementThe revolver wasn't one of the guns Westman used in the shootings at the Church of the Annunciation on Aug. 27, when it was full of students from the affiliated Annunciation Catholic School who had gathered for their first Mass of the academic year. Investigators recovered a semiautomatic assault-style rifle, a shotgun and a different handgun at the scene, and said Westman was legally entitled to buy them. Krause said none came from his store.Westman, 23, attended the school for eighth grade and Westman's mother formerly worked for the parish, but investigators are still trying to determine a motive. Westman died by suicide after firing 116 rifle rounds through the church’s stained-glass windows.As first reported by KSTP-TV, the security video shows Westman handling several firearms and talking with employees and other customers. Krause wasn't in the store at the time, but he said he promptly shared the video with investigators and is cooperating with them.Krause stressed that nothing in Westman's conduct raised any concerns among his staffers, who he said are trained to watch for warning signs.AdvertisementAdvertisementAdvertisementAdvertisement“This person said all the right things, they checked all the right boxes, asked all the questions, they were friendly, talkative, making jokes, laughing, knowledgeable about guns, handled a lot of guns that were not the type of guns you would think are of the interest of somebody looking to do a mass shooting,” Krause told the AP.Krause said his employees have extensive experience in picking out bad actors, straw purchasers, people who are homicidal, suicidal, mentally unstable or under the influence of alcohol or drugs. He said nothing stood out with Westman.“We're still going over it,” Krause said. “We’re still scratching our heads thinking, ‘What did we miss? What could we have done?’ But it always ends with the answer of ‘nothing.’ There was just nothing there. And that’s what makes this situation so unique.”A mother's pleaAdvertisementAdvertisementAdvertisementAdvertisementAt a news conference Thursday at Hennepin Healthcare, a trauma hospital that treated several victims, Annunciation parent Malia Kimbrell delivered a wrenching account about her daughter’s injuries and implored lawmakers to ban assault weapons.Her 9-year-old daughter, Vivian St. Clair, was shot three times: twice in the back and once in the arm. The girl, who had been in intensive care, is now recovering at home.“Her friend said to her, ‘Vivi, are you OK? You have a hole in your back,’” Kimbrell recounted.Kimbrell, a nurse in the hospital's newborn intensive care unit, challenged lawmakers to ban the kind of high-powered rifles and high capacity magazines used by the shooter, saying she will “settle for nothing less.”AdvertisementAdvertisementAdvertisementAdvertisement“I will get the names of any lawmakers who stand in the way of that happening, and I will invite you to come to my living room and insist that you hold Vivian’s hand while we do her dressing changes each night and she cries the entire time,” she said. “Action is our only hope. Thinking and praying are what you do after a tragedy. Taking action is what we can do before the next tragedy occurs.”The politics of changeDemocratic Gov. Tim Walz said Tuesday he intends to call a special session of the Minnesota Legislature to address gun and school safety, and he suggested that an assault weapons ban would be on his list of proposals, which he is still developing. But it would be very difficult for anything to pass the closely divided Legislature without at least some bipartisan support.House Republicans on Thursday released a list of proposals that lack any restrictions on access to firearms. It calls for increased funding for school security and for school resources officers, including for private schools. The proposals would also prohibit districts from banning school resource officers, as Minneapolis and some other districts have done.AdvertisementAdvertisementAdvertisementAdvertisementThe House GOP also called for more mental health treatment beds and mandatory minimum prison sentences for repeat criminals who use guns and for straw purchasers of firearms that are used in violent crimes.Students Demand Action, an arm of Everytown for Gun Safety, is organizing school walkouts across the country for Friday to demand that state and federal lawmakers ban assault weapons and high-capacity magazines.___Karnowski reported from Minneapolis. AP writer Sarah Raza contributed from Sioux Falls, South Dakota.