Once upon a time, misbehaving in school meant detention, or a conference wth your parents, or — in extreme cases — a temporary or permanent boot through the schoolhouse door. But with police officers increasingly stationed full-time on campuses across the country, violations of school rules now often result in handcuffs and criminal charges. School officials are increasingly handing even routine disciplinary matters to law-enforcement officers and the criminal justice system, according to a new report from the American Civil Liberties Union.

School rules themselves have become bizarrely strict over the years, and even the in-school penalties for transgressions have escalated. While those of us of school age in the 1970s commonly carried pocket knives without raising an eyebrow (my friends and I actually bought ours as souvenirs on a school field trip to Bushkill Falls, in Pennsylvania), to do the same these days is often automatic grounds for expulson. Arrested Futures: The Criminalization of School Discipline in Massachusetts' Three Largest School Districts by Robin L. Dahlberg, acknowledges this point, but says the problem continues to get worse:

While other research has focused on zero-tolerance policies and the overuse of out-of-school suspension and expulsion as significant factors in feeding the "School-to-Prison Pipeline," this report focuses on the additional problem of arrest, in particular the use of arrest to address behavior that would likely be handled in the school by school staff if not for the presence of on-site officers.

How common are police officers in the classroom? Frighteningly so, if you're the kind of person who thinks it should not take armed personnel to keep the lid on a place devoted to educating children.

Sixty years ago, in the mid-1950s, only Flint, Michigan employed police officers to patrol the hallways, lunchrooms and classrooms of its public schools. By 2005, however, 48% of public schools responding to a United States Department of Justice survey reported having on-site police officers. Today, there are an estimated 17,000 school-based officers.

Guns and badges are becoming a normal event in public school hallways, even though "school crime has declined significantly during the last 15 years," and "the total rate of self-reported school-based offenses per 1,000 students, including violent crime and theft, fell 69% between 1993 and 2008."

Which is to say, there's no real reason to replace a stern vice principal with cops. But, that replacement proceeds, and it has consequences.

Research has shown that the presence of on-site police officers frequently results in both more student arrests and more arrests for misbehavior previously handled informally by educators and parents. Districts that employ or deploy more police officers per student have higher rates of arrest than do districts with fewer officers per student. Those arrests frequently are based on behavior that, if not for the police presence, would not normally result in an arrest.

The specifics of police presences in the three districts studied — Boston, Springfield and Worcester — vary to a certain degree, but in all cases, law-enforcement responses are displacing traditional school discipline. The more overt the police presence, the more arrests. Armed, uniformed officers have a permanent presence in Springfield schools, with the result:

In 2007-08, Springfield had an arrest rate that was more than twice as high as Boston and seven times as high as Worcester. For every 1,000 students enrolled, there were 14 arrests in Springfield, six in Boston and two in Worcester. In 2009-10, Springfield's arrest rate was three times that of Boston's and five times that of Worcester's. For every 1,000 students enrolled, there were nine arrests in Springfield, three in Boston and two in Worcester.

And why were these kids cuffed and hauled away?

According to those reports, although a few public order offense arrests involved students who were so distraught that they were endangering the physical safety of those around them, most of the arrests occurred after students refused to follow the directive of a teacher, administrator or police officer in a verbally confrontational manner. Between one-quarter and one-third of the events that led to arrests for person offenses in Springfield began as public order offenses but escalated after an officer or teacher attempted to take control of the student. Several involved aggressive efforts by police officers to handcuff students who did not want to be handcuffed, often in a public hallway or stairway in full view of the students' peers.

So, we're not, by and large, talking about threats to persons or property; students are being arrested for incidents involving bad attitude, defiance and cursing. And, while most of those arrested are teenagers, some are as young as 11.

So … How is discipline handled where your kids are enrolled?