WASHINGTON (AP) — Armed security officers are becoming more prevalent at America's schools, according to a federal study released Thursday amid a heated debate over whether teachers and other school officials should carry guns.

Armed officers were present at least once a week in 43 percent of all public schools during the 2015-16 school year, compared with 31 percent of schools a decade before, according to data from a survey conducted by the National Center for Education Statistics.

Last month's mass shooting at a Florida high school put renewed focus on the role of armed school security guards, after a video showed that a sheriff's deputy at the school approached but did not enter the building where the attack was taking place.

The study came out a day after Education Secretary Betsy DeVos kicked off a federal school safety panel. DeVos has said that schools should have the option to arm teachers. She's being criticized by teachers' unions for not including educators, students and experts in the panel, which consists only of her and three other Cabinet secretaries.

The percentage of schools with a security guard, a school resource officer or other sworn law enforcement officer on campus at least once a week has gone up from 42 percent in 2005-06 to 57 percent a decade later. While security at schools of all grade levels increased, the shift is clearer among elementary schools, where the share with security staff has gone from 26 percent to 45 percent in the same time period.

"There has been an increase in security staff in school over the last 10 years and it's more pronounced at the primary school level," said Lauren Musu-Gillette, lead author of the report.

Experts, however, are divided on whether putting such officers on school campuses will make the schools safer or frighten children and lead to more arrests.

"There needs to be at least one in every school in the country," said Mo Canady, executive director of the National Association of School Resource Officers. "Every school could benefit from one."

School resource officers are sworn law enforcement personnel who have been trained to work in schools. Their duties include controlling outside traffic, patrolling the school, maintaining discipline, identifying problems and mentoring at-risk students, teaching law-related classes and serving as liaisons between schools and police. The school security study released Thursday includes school resource officers, other sworn law enforcement and additional security staff.

Ronald Stephens, executive director of the National School Safety Council, agrees, saying that trained officers carrying weapons can help prevent a shooting inside the school and deter a possible shooter from entering.

"It sends the signal that the school is being watched and that the care and supervision of children is an important priority," Stephens said.

Others have questions.

A 2013 congressional report found that the available research "draws conflicting conclusions about whether SRO programs are effective at reducing school violence."

"Also, the research does not address whether SRO programs deter school shootings, one of the key reasons for renewed congressional interest in these programs," the study said.

Critics of putting weapons in schools point to the sheriff's deputy in Parkland who stayed outside the school when 17 people were being killed. The officer, Deputy Scot Peterson, says he thought the shots were being fired from outside the school.

Ron Astor, an education professor at University of Southern California who specializes in school behavior, says that putting weapons in schools will make them akin to prisons, intimidate children and hurt their studies. Instead, he says, research has shown that violence, bullying and the use of drugs and guns is reduced in warm, caring environments focused on providing support to students.

"With a lot of guns, it doesn't create a sense of safety with the children and the teachers. It could trigger post-traumatic stress disorder. It triggers nonattendance," Astor said.

"We don't want to live in neighborhoods where there are thousands of police officers or the military. Who likes to live in those neighborhoods?" he said. "We like to live in neighborhoods where we know each other, where people have good relationships with each other, where they are out on the streets, talking to each other."