Over five years ago, after I had written an op-ed lambasting the easy access the Sandy Hook shooter had had to assault-style firearms and ammunition, I received a small package in the mail. There was no return address. No note inside. Lots of tape. When I worked for Congress, this kind of mailing would have been opened only in a bomb- or anthrax-secure room. But I opened it anyway. Inside was a sticker with a handgun printed inside a red circle with a line drawn through it. Around the circle, it read: “Gun Free Household.”

Given the slew of nasty, threatening emails that had singled me out because of my newspaper piece, I figured it was intended as a dare. “Put this on your door,” the sender seemed to mock. “Let’s see just how little you value having the protection of a gun in your house.” So I put it up.

I guess that makes my small house a soft target. Softer still because I leave my not-very-strong 19th-century doors unlocked sometimes. No dog barks at the sound of a visitor. Yet I feel safe in Maine, and a gun in my house would make me feel unsafe. That’s me, and I’m not suggesting that it’s for everyone. But why I feel safer says something about why the notion of teachers carrying guns sickens me.

I have studied gun violence. I know the statistics, at least as much as the National Rifle Association allows to be collected. I know that lawfully carrying a concealed weapon increases the chance of gun violence, and not against bad guys. Remember the toddler who lifted a loaded gun from his mother’s purse in Walmart and killed her? Or the Good Samaritan who arrived at a mass shooting scene in Arizona and nearly shot the wrong man?

Think of the many suicides in Maine, where a temporary self-destructive impulse led to certain death because a gun was around. Read the obituaries. When you read that a man between the ages of 45 and 64 “died unexpectedly at home,” you can bet it was probably suicide by gunshot. So while I agree that the Second Amendment protects the right of citizens to own guns, it is a choice that can be much more dangerous for everyone in the family than a home intruder could be.

This makes me leery of the call by President Donald Trump and the NRA to arm some teachers. Teachers and superintendents across the country are aghast. What does this spell for the trust so important between students and their educators, they ask? Will it stop mass shooters, or simply put teachers in the line of fire from police or the shooter? And what about the usual roughhousing that is part of high school life in many places? Will scuffles escalate to deaths if a gun is part of the mix? These are unknowns — but then so is the supposed extra safety that would come from arming people who’ve been trained as teachers, not SWAT agents.

What really makes me shudder, though, is the easy availability in America of military-style firearms and large-capacity magazines. They may be fun to collect or fire at the range, but aimed at a person, they are designed to blast away with enormous power. Remember the Republican congressman shot at a baseball game last year? The bullet to his hip almost killed him because it tore through his body, pulverizing many internal organs. Trauma surgeons have made this point over and over. A bullet from a common rifle or handgun usually goes in and out, and unless a vital organ is directly hit, the patient survives. A bullet from an AR-15 does massive, usually fatal destruction.

If Americans want to do something useful in the wake of Parkland, ban these weapons and magazines, as we did from 1994 to 2004 after the shooting of President Ronald Reagan and his press secretary, Jim Brady. Congress let that law expire for no good reason. While on the books, there were no gun confiscation programs.

The law was never intended to cut gun violence across the board, and did not. But it met its stated goal of reducing the frequency and lethality of mass shootings (six or more deaths), University of Massachusetts at Boston researcher Louis Klarevas has found: In the decade before the law, 19 mass shootings occurred, causing 155 deaths. When the law was in place, incidents fell to 12 and deaths to 89. From 2004 to 2014, incidents shot up to 34 and deaths to 302.

AR-15 and AK-47 variants are among the most popular firearms on the market now. Proliferation means they are easy to get. And use. So when people say nothing can be done that is effective, I — like the teenagers in Parkland — call BS.

Janice Cooper is a Democratic state representative from Yarmouth.