A growing share of public primary schools in the United States have sworn law enforcement officers on site.

According to Pew Research, "An estimated 36% of U.S. public primary schools had sworn officers on site at least once a week in the 2015-16 school year, up from 21% a decade earlier, according to the report from the National Center for Education Statistics and the Bureau of Justice Statistics. The share of primary schools with an officer present grew much faster during this period than the share of secondary schools with an officer on site, which increased from 58% to 65%."

The presence of officers at primary schools differed by the size of the school., said Pew: A quarter of schools with fewer than 300 students reported officers on site, compared with 42% of schools with 500 to 999 students. 

Few primary schools with officers on site at least once a week reported that officers were at school for all instructional hours every day (13%). In contrast, 85% of primary schools with officers present said these officers were on site at some point during school hours, while smaller majorities said officers were at school when students were arriving or leaving (67%) or at selected school activities, such as science fairs or athletic events (60%).

While only 36% of U.S. primary schools had officers on site, the vast majority of those schools (86%) reported that officers routinely carried a firearm. According to Pew Research, primary schools in cities were less likely than those in towns and rural areas to report that officers carried a firearm. Across all community types, 32% of primary schools with officers present reported having formalized policies or written documents specifically about officers’ use of firearms.

The recent study also found that most primary schools report being prepared for certain crisis scenarios, said Pew Research. The vast majority of primary schools overall (91%) had written procedures to be followed in a shooting scenario, up from 76% in 2003-04. Similarly large majorities of primary schools had written procedures for bomb threats or incidents (93%) and natural disasters (96%). Furthermore, large majorities of primary schools conducted lockdown (96%), evacuation (91%) and shelter-in-place (75%) drills during the school year.

http://www.pewresearch.org/fact-tank/2018/05/15/rising-share-of-u-s-primary-schools-have-sworn-officers-on-the-premises/