Some of the shootings at schools this year were suicides that injured no one else; some did not result in any injuries at all. But in the years since the massacres at Columbine High School in Colorado, Virginia Tech and Sandy Hook Elementary School in Newtown, Conn., gun safety advocates say, all school shootings seem to have lost some of their capacity to shock.
Shannon Watts, the founder of Moms Demand Action, a gun safety group, said that’s because in 2012 in Newtown, “20 first graders and six educators were slaughtered in an elementary school.”
“The news cycles are so short right now in America, and there’s a lot going on,” she said. “But you would think that shootings in American schools would be able to clear away some of that clutter.”
Gov. Matt Bevin of Kentucky said the gunman who opened fire Tuesday morning at Marshall County High School in Benton, near the western tip of the state was a 15-year-old student. The authorities said the student entered the school with a handgun just before 8 a.m., fired shots that struck 14 people, and set off a panicked flight in which five more were hurt.
One girl who was shot, Bailey Nicole Holt, died at the scene; a boy, Preston Ryan Cope, died of his injuries at a hospital.
The suspect, who was not immediately identified, was taken into custody in “a nonviolent apprehension,” Mr. Bevin said, and officials said he would be charged with two counts of murder and several counts of attempted murder. But the authorities had not yet decided whether the charge the suspect, who was armed with a pistol, as a juvenile or as an adult.
Of the 17 people injured, five remained in critical condition, law enforcement officials said on Tuesday night.
“This is something that has struck in the heart of Kentucky,” Lt. Michael B. Webb of Kentucky State Police said at a news conference. “It’s not far away, it’s here.”
Not for the first time. The region was scarred about two decades ago by a deadly school shooting in West Paducah, about a 40-minute drive away. Three people were killed when a student opened fire into a prayer circle, and five more were injured.
Benton is a small town about 200 miles southwest of Louisville, and its high school serves students from all over Marshall County, with a population of about 31,000.
John Parks, who owns the Fisherman’s Headquarters store about a mile from the school, described the area as a “very close-knit community” where just about everyone would have known a student at the school. “It’s personal when it’s a small town like this,” he said.
The town of Italy, Tex., isn’t any bigger than Benton. On Monday, a 15-year-old girl there was hospitalized after she was shot by a 16-year-old classmate, according to local news reports. That suspect, a boy, was taken into custody by the Ellis County Sheriff’s Department. The authorities said on Tuesday that the victim was recovering.
The F.B.I. study that Ms. Schweit helped write examined active shooter episodes in the United States between 2000 and 2013. It found that nearly one-quarter of them occurred in educational environments, and they were on the rise.
In the first half of the study period, federal officials counted 16 active shooter incidents in educational settings, meaning instances of a person “actively engaged in killing or attempting to kill people in a confined and populated area.” In the second half, the number rose to 23. (Many, but not all, of the school shootings tallied by advocates so far this year meet that definition.)
“Any time there’s a school shooting, it’s more gut-wrenching, and I think we have a tendency to react in a more visceral way,” Ms. Schweit said in an interview on Tuesday. “But I really don’t think as a whole, in society, we’re taking shootings more seriously than we were before — and that’s wrong.”
Even so, jarred and fearful school administrators across the country have been placing greater emphasis on preparing for the possibility of an active shooter. According to a report issued by the Government Accountability Office in March 2016, 19 states were requiring individual schools to have plans for how to deal with an active shooter. Only 12 states required schools to conduct drills, but two-thirds of school districts reported that they had staged active shooter exercises.
School safety experts say steps like the drills are crucial, if imperfect, safeguards.
“I think we’ve become somewhat desensitized to the fact that these things happened, and it takes a thing like Sandy Hook to bring us back to our senses,” said William Modzeleski, a consultant who formerly led the Department of Education’s Office of Safe and Drug Free Schools.
“My fear is that if you don’t hear about a school shooting for a while, educators move on to other things,” he said. “Principals are busy. Teachers are busy. Superintendents are busy.”
In Kentucky, lawmakers have grappled with how to address the risk of school shootings. Last year, state legislators considered, but did not pass, a bill that would have allowed people with concealed-carry permits to bring weapons on to public school campuses, where proponents argue they could be used to respond to active shooters. A similar bill, limited to college campuses and certain other government buildings, has been introduced this year. It was not immediately clear how the shooting in Benton might affect the debate in Frankfort, the Kentucky capital.
But in Benton, “this is a wound that is going to take a long time to heal,” said Mr. Bevin, the governor, “ and for some in this community, will never fully heal.”