Monday was a big day in the evolution of U.S. criminal justice policy. U.S. Attorney General Eric H. Holder Jr. announced that federal prosecutors would no longer pursue mandatory minimum sentences for low-level, nonviolent drug offenses. And a federal district court judge ruled that New York’s “stop-and-frisk” policy has an unconstitutionally disproportionate impact on minority men.

These moments were a long time coming.

At our low point in the late 1980s and early 1990s, the explosion of crack cocaine, coupled with an influx of semiautomatic handguns, sent homicide rates skyrocketing around the country, especially among black and Latino males. Back then, when D.C. was sometimes said to stand for Dodge City, the District had nearly 500 killings a year. Drug crews virtually controlled swaths of the city, with many streets and playgrounds off limits to law-abiding residents.

In hindsight, the result was panic. In a desperate attempt to respond to public demands for safer neighborhoods, officials adopted the aggressive tactics and draconian sentencing that overburdened our jails.

When I became a federal prosecutor in the District in 1990, the war on drugs was raging: Police jump-out squads routinely rousted black males on the streets, while prosecutors and judges hammered defendants with long sentences, even in nonviolent drug cases. The theory was that longer sentences would deter drug dealing and the violence that came with it, but the result was an explosion of incarceration. The United States became the world’s greatest jailer, with nearly 2 million Americans in prison.

By the time I was elected state’s attorney in Prince George’s County in 2002, it was clear that this war was devastating black communities. Residents of violent neighborhoods certainly wanted help, but they saw that we were never going to jail our way out of the problem. They sought a balanced approach: tough sentencing for the most violent offenders, but intervention for first-timers who might benefit from substance-abuse treatment, educational and training programs, and counseling. My political advisers said we had to be tough on crime, but the voters said we should be smart on crime. We finally began to hear that message.

At the same time, state and local officials began to question the wisdom of mass incarceration. The budgetary burden of over-incarceration began to force state and county legislators — even in conservative states such as Alabama — to test alternatives such as electronic monitoring, outpatient drug treatment and other alternatives to prison.

In addition, innovative academics such as John Jay College’s David Kennedy and Yale’s Tracey L. Mears developed violence-reduction strategies that performed well in high-crime areas. Police and prosecutors learned that combining input from neighborhood leaders with the expanded use of technology to target actual troublemakers was more effective than saturation patrols and generalized stop-and-frisk tactics. The improved community relations also paid dividends in the courthouse: Targeted enforcement generated fewer suspicious jurors and uncooperative witnesses.

While these are all positive developments, it’s way too early for a victory lap. The bellicose response from New York’s mayor and police chief to the stop-and-frisk ruling shows that there will certainly be push-back from hawks who continue to believe that more incarceration is always better.

Five points on how we continue to move forward from here:

First, elections matter. The coalition of liberals, libertarians, budget hawks and law enforcement leaders who laid the groundwork for Monday’s victories needs to be fully engaged in the next round of elections, especially at the city and county levels. Judicially appointed monitors like the one in New York make little headway with street cops whose bosses — police chiefs and the executives who appoint them — remain committed to their old approaches. Selecting the right mayors, prosecutors, police chiefs and judges will have a bigger impact than monitors ever could.

Second, while Holder’s announcement on mandatory minimums was welcome, we should also remember that the minimums were partly intended to address disparities by increasing sentences across the board. Of course, the sentences were too draconian, but they narrowed disparities between black and white, rich and poor. Vigilance is needed: The Supreme Court’s elimination of mandatory sentencing guidelines, coupled with the Justice Department’s de-emphasis of mandatory minimums, could mean disparities will grow again.

Third, the smart-on-crime coalition needs to be fully engaged in the legislative process. Holder’s announcement only affects federal criminal cases. The vast majority of mandatory minimum sentences are imposed in state courts. Targeted legislation to eliminate mandatory minimums for drug and nonviolent offenders are the highest priority. Leave mandatory sentences in place for violent offenders — especially murderers, sexual predators and drug kingpins.

Fourth, we need to focus on the appointments process. Holder’s background is without precedent as an attorney general: Not only did he toil as a local prosecutor and judge during the District’s crack epidemic, but also he’s a black man who understands the searing embarrassment of random police stops. It might be a long time before we have another attorney general like him. His successors must stay the course.

Finally, we need credible studies that give a better sense of which crime strategies work and why. While we know that the consequences of our war on drugs have been unbearable — especially in black communities — we need more guidance on which new approaches to use. It’s also important to figure out whether the steep declines in violent crime are based on local crime-reduction strategies or whether they have been driven, in places like Manhattan and the District, by pushing low-income people to the suburbs.

Glenn Ivey, a partner in the D.C. law firm of Leftwich & Ludaway, was state’s attorney for Prince George’s County from 2002 to 2011.