SOUTH PORTLAND — More than five years ago, my 25-year-old daughter, Darien, was asleep in her bed in her Portland duplex when masked intruders burst into her bedroom and started shooting.

Darien was shot several times: One bullet traveled the length of her thigh and lodged in her hip, where it remained. Another bullet shredded the thumb of her left hand.

She was rushed to the hospital, where she spent two days in intensive care and 18 more days as an in-patient. We watched her suffer for weeks in great physical and emotional pain as she worked hard to recover, but tragically, our beautiful and vibrant daughter died of complications caused by her gunshot wounds.

To this day, my daughter’s homicide remains unsolved. But investigators did recover the gun used in her murder. Sadly, it was linked to the murder of a young man in Portland just one month later.

The investigation of our daughter’s case went cold there – in part, we learned, because the .45-caliber handgun that was linked to both shootings had been sold through a “private” sale in Maine at a gun show, no background check, no questions asked.

Think about that: Two young people dead from the same handgun that was sold without a background check.

The stalled investigation into Darien’s murder is a prime example of why we need to close the loophole in Maine law that makes it easy for criminals to get their hands on guns. While all gun buyers at licensed dealers must pass a criminal background check, no background check is required when you buy from an unlicensed, private seller – whether at a gun show, online or via ads in the Uncle Henry’s shopper.

The tragic truth is that gun violence happens not just in big cities but all throughout America, including right here at home in Maine. It kills our friends and members of our communities and devastates families. Some 88 Americans die by gunshot each day in this country (including homicides, suicides and accidental deaths) – and hundreds more are injured.

Gun violence took our daughter and silenced her voice. But my husband, Wayne, and I will never stop speaking for Darien. And what we continue to say in her name is: We must do more to prevent gun violence.

That’s why we are part of a group of committed people who are working to close the background check loophole. With the backing of the Maine Moms Demand Action for Gun Sense Fund, Wayne and I recently took the first steps toward giving Maine voters the chance to vote on a background check ballot measure in November 2016. We submitted the initiative along with other Maine citizens including law enforcement, advocates for preventing domestic violence, gun owners and parents.

If passed, this measure would require criminal background checks on all gun sales, with reasonable exceptions for family, hunting and self-defense. An unlicensed seller would simply meet the buyer and complete the sale at a gun dealer, who would run the same instant criminal background check they do on their own gun sales.

Requiring all gun sellers to follow the same rules represents a simple and common-sense policy that would make it more difficult for criminals to get their hands on deadly weapons.

While no law can prevent every tragedy, research shows that background checks work. In the states that require criminal background checks on all handgun sales, 48 percent fewer law enforcement officers are killed with handguns; 46 percent fewer women are shot to death by intimate partners; and 48 percent fewer people take their own lives with a gun. These numbers cannot be ignored.

Wayne and I are lifelong Mainers. We have met countless Maine gun owners who support background checks on all gun sales and who don’t understand how anyone could oppose such a sensible idea.

In fact, 80 percent of Maine voters support background checks on all gun sales. That includes gun owners and hunters, such as my husband, who know that respecting the Second Amendment goes hand in hand with personal responsibility.

Background checks are quick and easy. In fact, more than 90 percent of federal background checks are conducted within two minutes. And more than 98 percent of Mainers live within 10 miles of a gun dealer, making it simple and convenient for buyers and sellers to meet at a licensed gun dealer to run the check. Gun owners are already used to passing background checks, and know it’s a small sacrifice to make in order to ensure guns are not falling into the wrong hands.

Sometime after Labor Day, we expect the background check initiative will be cleared for signature gathering, and Mainers will finally get a chance to have their say on this issue. I urge all voters to sign the petition putting background checks on the November 2016 ballot. And in 15 months, please vote “yes” to close the dangerous loophole that puts our children, families and communities at risk. It’s too late to save our Darien, but it’s not too late to save other lives.