Two mass shootings in less than 24 hours left at least twenty-nine people dead in the United States Sunday.The shootings happened in El Paso, a Texas city along the Mexico border and Dayton, a city in the state of Ohio 2500 kilometers northeast.At about 10:40 a.m. Saturday morning, officials said, a gunman walked into a Walmart store in El Paso, Texas and began shooting.Hundreds of people were in the store.Many were buying back-to-school clothes and supplies for their children.Police said twenty people were killed and 26 were wounded in the violence.Among those killed was Jordan Anchondo who died while trying to protect her 2-month-old son from bullets.Police arrested the shooting suspect at the attack site.He is identified as Patrick Crusius, a 21-year-old man from Allen, Texas, a city about 10 hours from El Paso.Officials are investigating whether he is connected to an online document denouncing the Hispanic population in the U.S. and immigrants, generally.The U.S. Census estimated the border city of El Paso has a population of 682,000.More than 80 percent of the people in El Paso identified themselves as Hispanic or Latino.El Paso Sheriff Richard Wiles expressed his anger on a Facebook post.He wrote, "This Anglo man came here to kill Hispanics. I'm outraged and you should be too."John Bash is the U.S. Attorney for the Western District of Texas.On Sunday, Bash said the Justice Department is treating the shooting as a case of domestic terrorism.He added the department is "seriously considering" bringing federal hate crime charges against the suspect in the El Paso shooting.The charges could carry a death penalty.While Americans were still following the news of the killings in El Paso, another gunman attacked at about 1:00 a.m. Sunday in Dayton, Ohio.The man wore body armor, carried extra bullets and opened fire in a socially busy area described as "a safe part of downtown."Nine people were shot to death and 16 were wounded.Police killed the man within a minute of the gunman's first shot.A witness told the Associated Press that the gunfire was "rapid" and "people were just falling."Officials said the shooter was Connor Betts, a 24-year-old white man.They said his 22-year-old sister, Megan, was the youngest to die in the attack.The oldest was 57.Dayton Mayor Nan Whaley praised the police for their quick reaction.Otherwise, she said, "hundreds of people in the Oregon District could be dead today."A week ago, another gunman killed three people and wounded 13 others at a public celebration in Gilroy, California.The U.S. Justice Department defines mass killing as an event in which three or more people are killed.The New York Times reports 32 mass killings in the United States so far for 2019.U.S. President Donald Trump called the shooting in El Paso "an act of cowardice."He wrote on Twitter, "I know that I stand with everyone in this Country to condemn today's hateful act.There are no reasons or excuses that will ever justify killing innocent people...."Democrats, however, were quick to blame the president for the violence.Beto O'Rourke, a Democratic Party presidential candidate from El Paso, blamed Trump's recent attack and comments on people of color for the violence."He is encouraging this. He doesn't just tolerate it; he encourages it," O'Rourke told CNN.Acting White House chief of staff Mick Mulvaney later told ABC News that Trump was "saddened by this and he's angry about it.""These are sick people," Mulvaney added."And we need to figure out what we can do to make sure this doesn't happen again."