In 2015, more than half of the people arrested by Honolulu police were mentally ill. Close to half were homeless, according to police department statistics.

Many of them were arrested for low-level, nonviolent offenses. And because of drug addiction or mental illness, they often don’t respond to the punishment of jail time, leading to high rates of repeat offenders.

It is a foolish waste of the state’s resources to continually book, process and lock them up. And we’re not only throwing money away, we’re also exacerbating the problem by further traumatizing vulnerable citizens.

These figures are especially appalling considering Hawaii’s prisons are already woefully overcrowded. The state’s four jails were operating at more than double their designed capacity at the end of December, and just two weeks ago, the American Civil Liberties Union of Hawaii called for a federal probe into seven of the state’s prisons and jails, saying that the conditions amount to an infringement of prisoners’ constitutional rights.

The situation begs the question: If it’s causing more harm than good, why do we keep putting these people in jail?

As Civil Beat’s Anita Hofschneider reported, Seattle asked itself that question in 2011 and came up with a new plan. The city developed the Law Enforcement Assisted Diversion program, which gives people arrested for low-level drug offenses or sex work the option of receiving social services instead of going to jail.

The city saw almost immediate improvement: Almost half of the homeless participants got housed and more than half received drug treatment. Six other jurisdictions have since adopted the model, and now Gov. David Ige wants Hawaii to experiment with it.

It’s a great idea and, frankly, it’s about time.

The glaring problems of homelessness and prison overcrowding have reached crisis points. Thus far, the state’s responses have been limited to little more than trying to move the problems out of sight and out of mind. We ship our inmates to the mainland with almost no oversight or accountability, and we pass ineffective sit-lie bans that shuffle homeless people from one neighborhood to another.

Meanwhile, Hawaii’s so-called Justice Reinvestment Initiative aimed at promoting rehabilitation and reduce recidivism has languished for years.

The LEAD model is that rare public policy that might help solve two major problems by reducing jail overcrowding and homelessness.

Its real innovation, however, is its ability to do this for a fraction of the cost of other solutions and to do it faster.

If it’s causing more harm than good, why do we keep putting these people in jail?

Consider, for a moment, that Ige wants the Legislature to spend just $200,000 on a pilot program, part of the $20 million he wants for homeless services like rental assistance. The Hawaii Department of Public Safety is also requesting $9 million in capital improvement funds to expand the capacity of the Women’s Community Correctional Center. That expansion would help accommodate 140 female inmates from the Oahu Community Correctional Center and would likely take years to finish.

By comparison, Seattle devoted $400,000 for its pilot program, which served about 65 people. The program was so effective at reducing criminal behavior that the savings were obvious and the state doubled down on the strategy.

Seattle currently spends $2.1 million on LEAD, serving more than 400 people.

“Even providing a Cadillac level of services to them is cheaper than the criminal justice system,” Kris Nyrop, who helped start the program in Seattle and recently visited Honolulu to advise local service providers, told Hofschneider.

Considering the Hawaii Council on Revenues has dropped its estimate of 2017 tax revenue by $155 million, the Legislature is going to have to make prudent and cost-effective choices for the budget.

A LEAD-like program might just offer a pretty big bang for the buck.