In one of his last interviews in office, former Gov. Jay Nixon was asked if he had any regrets on his 30-year career in public service.

Nixon, also a former attorney general, said one of his regrets was not being able to stem the state’s growing prison population.

Nixon’s lament was an acknowledgement of a problem that doesn’t receive a lot of attention outside of criminal justice circles and one that is at odds with the popular mindset of “lock ’em up and throw away the key” when it comes to law and order.

But it should. Missouri’s incarceration rate is the eighth highest in the country and the highest for women.

There are about 32,500 people incarcerated in our state’s prison system with another 5,000 or so temporarily passing through for screening, treatment or other reasons.

That’s according to The Council of State Governments Justice Center, which recently completed a comprehensive study of the state’s prison system at the request of Gov. Eric Greitens and other state officials.

Some may conclude that our state’s higher-than-expected incarceration rate is nothing more than a reflection of a growing crime problem. That is certainly a concern we hear on a regular basis from our readers.

Those perceptions are bolstered by recent reports of disturbing criminal acts, like the alleged sexual abuse of an 8-year-old girl whose perpetrator made her eat methamphetamine and smoke marijuana in a Washington hotel.

When crime hits close to home, it’s easy to be alarmed. While the state’s overall crime rates have fallen in the past two decades, Missouri’s crime rate remains well above the national average and violent crime has increased in recent years, rising 20 percent between 2013 and 2016.

The question is what can we do about it? The easy solution, and the one Missouri has historically followed, is to “lock ’em up.” That is why Missouri’s prison system is running at 105 percent of capacity. We don’t hesitate to incarcerate. People want that!

That approach is why, in part, more criminals are incarcerated in county jails and why some counties, including ours, need to expand their jail facilities.

The Justice Center prison study warns that if the state doesn’t act to change the trajectory of incarceration rates, two new prisons will be necessary to accommodate the increase.

But prisons are expensive to build and operate. A more thoughtful approach must include solutions aimed at addressing the root causes of crime.

The study recommended investing $189 million over the next five fiscal years to expand and improve options to treat offenders in the community for behavioral health problems and substance abuse.

That makes more sense than investing many more millions in more prisons. Attack one of the primary causes of crime and you can turn the incarceration rate around. Drugs and crime go hand in hand. Those who work in the criminal justice system can attest to this reality.

The study is spot on in recognizing the lack of community behavioral health treatment resources exacerbate pressures on the criminal justice system.

The facts speak for themselves. A staggering 88 percent of people entering Missouri prisons are assessed as needing substance use treatment and 14 percent as needing treatment for mental illnesses.

Spending money on community treatment resources may not be as politically popular as building more prisons, but in the long run it represents a more effective solution. We hope our legislators read this report.