On a night of the Republican convention focused on "making America safe again," one question, strangely, went unanswered: How exactly could policymakers make America safer? Although Americans are in fact safer than they were decades ago, this seems like a pretty crucial question to answer given the first day of the convention's theme.

I previously reached out to criminologists and researchers across the country about this issue. My question: What nonpartisan policies can America use to reduce crime and gun violence without going after the guns themselves? I started with the assumption that gun control laws would not happen, since that issue is too politically fraught — and it's certainly not something Republicans seem likely to support.

After all, although there's strong evidence that America's uniquely high levels of gun ownership cause the US to have more violence than other developed countries, guns aren't the only cause of violence and crime — there are other factors, from cultural issues to socioeconomic variables to even smaller issues like alcohol consumption, that drive these problems.

What follows are six of the promising ideas I heard to reduce crime and gun violence in particular. This is by no means a comprehensive list — there are great websites solely dedicated to that kind of catalog. But these policy ideas give some perspective on how many options are left to local, state, and federal lawmakers as long as they don't want to do anything about guns — or maybe even if they do.

1) Stricter alcohol policies

Alcohol has been linked to violence. According to the National Council on Alcoholism and Drug Dependence, alcohol is a factor in 40 percent of violent crimes. And a 2010 study found a strong relationship between alcohol stores and gun assaults. These statistics and research are one of the big reasons that possessing a gun while drunk is largely illegal.

"It's a disinhibition theory," Charles Branas, one of the 2010 study's authors, said. "So it's not so much aggressiveness, but that decisions and judgment that would normally be held in check are suddenly disinhibited under consumption of alcohol."

This doesn't mean America should ban alcohol — prohibition in the 1920s was a disaster. But there are other policies that America could take up to limit alcohol-related problems:

A higher alcohol tax : A 2010 review of the research in the American Journal of Public Health came out with strong findings: "Our results suggest that doubling the alcohol tax would reduce alcohol-related mortality by an average of 35%, traffic crash deaths by 11%, sexually transmitted disease by 6%, violence by 2%, and crime by 1.4%."

: A 2010 review of the research in the American Journal of Public Health came out with strong findings: "Our results suggest that doubling the alcohol tax would reduce alcohol-related mortality by an average of 35%, traffic crash deaths by 11%, sexually transmitted disease by 6%, violence by 2%, and crime by 1.4%." Reducing the number of alcohol outlets : A 2009 review published in the American Journal of Preventive Medicine also found that limiting the number of alcohol outlets — through, for example, stricter licensing — in an area can limit problematic drinking and its dangers. But it also found that going too far can have negative results — by, for example, causing more car crashes as people take long drives to outlets and possibly drink before returning home.

: A 2009 review published in the American Journal of Preventive Medicine also found that limiting the number of alcohol outlets — through, for example, stricter licensing — in an area can limit problematic drinking and its dangers. But it also found that going too far can have negative results — by, for example, causing more car crashes as people take long drives to outlets and possibly drink before returning home. Revoking alcohol offenders' right to drink: South Dakota's 24/7 Sobriety program effectively revokes people's right to drink if a court deems it necessary after an alcohol-related offense. The program, specifically, monitors offenders through twice-a-day breathalyzer tests or a bracelet that can track blood alcohol level, and jails them for one or two days for each failed test. Studies from the RAND Corporation have linked the program to drops in mortality, DUI arrests, and domestic violence arrests.

Notably, the NRA, the biggest gun rights group, already agrees alcohol and guns don't mix. Its website says, "Never use alcohol or over-the-counter, prescription or other drugs before or while shooting." The question, Branas said, is how to make that "operational" — and some of these policies could move in that direction.

2) Hot-spot policing

Yes, police practices have run into increasing criticism over the past couple years — with the advent of the Black Lives Matter movement and its protests against racial disparities in the criminal justice system and police use of force.

But police can, obviously, play a huge role in reducing crime, especially by adopting evidence-based tactics like hot-spot policing.

The idea, explained to me by famed criminologist David Kennedy: In many cities, a very small subset of places, down to the street and block level, drive most of the crime. So deploying police, intelligently, in these specific areas can have a big impact on fighting crime and violence.

In many cities, a very small subset of places, down to the street and block level, drive most of the crime

"It can be as simple as making sure your police presence is increased there, or it can be much more complicated," Kennedy said. "You can get partnerships of police, residents, families, parents, shop owners, building managers, and school officials." He added, "The more those interventions involve partnerships, the more effective those interventions can be."

The research strongly backs up the practice: Not only does it reduce crime, but it does so without displacing it to other areas and generally to positive reactions from locals. And as Kennedy said, the research suggests that bringing in community partners and focusing on the community's needs can boost the crime-fighting effects further.

3) Focused deterrence policing

One of the hot new phrases in criminal justice today is "community policing." But quite honestly, nobody seems to have any idea what it means. Experts and law enforcement officials will give all sorts of definitions and strategies for the practice.

But Kennedy did explain a strategy — "focused deterrence policing" — that sounds a lot like what I would expect real community policing to look like, and it works.

Focused deterrence hones in on specific problems in a community, such as drug dealing, generally violent behavior, gangs, or gun violence. It then focuses on the individuals and groups who drive most of that activity, particularly those with criminal records and those involved in gang activity.

"The national annual homicide rate now is between 4 and 5 per 100,000," Kennedy said. "If you're in one of these street networks, your homicide rate can easily be 3,000 per 100,000." He added, "Add in the nonfatal woundings, which can be multiples of the homicide rate, and suddenly you're in unimaginable risk."

"The community itself needs to convey extremely strong and clear standards against the violence"

The strategy brings together law enforcement and community groups to clearly signal the major legal and community consequences of violence, especially in relation to an individual's previous criminal record. And to provide alternatives to violent or criminal lifestyles, the community should also offer social services and other forms of help.

So if someone has a long history of drug or even violent crimes, police could let him know about the legal consequences of violence — decades or life in prison — and the community could voice, through personal interactions, how it would directly damage his family, friends, church, school, and so on. And the groups should also offer help through, for example, accessible job and education programs.

"The community itself needs to convey extremely strong and clear standards against the violence," Kennedy said, describing it as a form of informal policing that comes from within someone's community.

The idea is that a would-be shooter, now knowing the full consequences of his actions, will be deterred from acting out in the future. And he'll have alternative options if he wants to pursue a different kind of life.

The research shows this works. Focused deterrence is one of the changes in policing strategy credited with what's known as the "Boston miracle," in which the city saw violent crime drop by 79 percent in the 1990s. And other research has found that it can work in many other places.

This policing strategy can involve retraining cops, getting them more involved in the community, hiring more officers to carry it out effectively, and boosting spending on social services. That can be very expensive — as such services and police departments already make up a sizable chunk of many municipal and state budgets. But if local lawmakers and officials want to reduce crime, these changes can go a long way.

4) Raise the age or grade for dropping out of school

Another way to reduce crime and violence could be to keep kids in school longer.

The research is quite clear that kids who don't drop out and complete school are less likely to commit crime.

But this can get into tricky questions over correlation versus causation: Does keeping kids in school longer stop them from committing crime later on by keeping them off the streets and giving them the education they need to find a legal job? Or are the kids who decide to stay in school longer simply better behaved, and therefore less likely to commit crimes?

A recent study published in the American Economic Journal took an ingenious approach to cut through this question — by tapping into data for students in North Carolina, their birthdays, when they enroll in kindergarten, their dropout rates, and their crime rates. It found that keeping kids in school longer likely reduces crime.

The study looked at data based on when children begin their education and whether the older children in a class — those who were enrolled into kindergarten at an older age — were more likely to drop out and commit crime. The idea: These kids are generally enrolled at a later age due to a technicality in North Carolina rules about birthdays and cutoff dates, so there's no inherent reason to think their behavior should be different — unless their time in school influences it.

The study strongly suggests keeping kids in school will reduce their crime rates

The study found that these older kids were more likely to drop out — and they were more likely to commit a felony offense by age 19.

Phil Cook, one of the study's authors, told me his findings strongly suggest keeping kids in school will reduce their crime rates.

So what could policymakers do with these findings? Well, many states, including North Carolina, set the dropout age at 16. They could raise the dropout age to 18 or older.

"If North Carolina raised its age to 18, there would be some seniors in particular who'd cross that threshold and would be legally entitled to drop out," Cook said. "But that prospect would look different than it does at age 16 — they would be closer to the finish line, so presumably it would not be as enticing."

Another option: Lawmakers could adopt Denmark's model, which requires students to complete a certain number of grades. (Presumably there would be exceptions, such as for children with extreme disabilities.) This would be less arbitrary than an age cutoff, but it could run into some politically tricky territory if it forces adults 18 and older to stay in high school.

Whatever method policymakers use, keeping kids in school longer appears to reduce crime rates. And it doesn't involve guns at all.

5) Behavioral intervention programs

The University of Chicago Crime Lab has done a lot of great work into many different policy proposals to fight crime. One of those ideas, Youth Guidance's Becoming A Man, is emblematic of how specific these policies can get — it targets youth who are at risk of getting into violent encounters, perhaps because of the neighborhood they live in or what school they go to.

The program then uses once-a-week interventions, based on cognitive behavioral principles, to teach youth how to react in encounters that can turn violent.

"It helps kids understand and slow down the scripts that they use to get by," Harold Pollack, co-director of the Crime Lab, said. "They have exercises that the kids do where they get to practice self-regulation, skills, and slowing down and negotiating with other people — the kinds of things that young boys growing up particularly in a tough environment haven't had enough of a chance to practice."

It works: Randomized control trials by the Crime Lab found it reduced violent crime arrests by 30 to 50 percent during the time of the intervention.

"It helps kids understand and slow down the scripts that they use to get by"

One example of the exercises the program uses: One kid is told to get a golf ball from another kid. Typically, they get in a physical fight within seconds, because they simply don't know any better. But when they're walked through the situation, they learn to resolve it much more peacefully.

"So many of the confrontations that kids get into are almost over nothing in one sense," Pollack said. "But in another sense, kids are in a situation where they've learned over a period of time a set of reactions that are pretty important for them so that everybody knows not to mess with them."

The problem, Pollack said, is that many of these kids simply haven't learned the right behaviors over time — and they've actually learned to resort to violence quite quickly. Pollack gave an example:

For example, I'm walking down the hallway and somebody steps on my foot in school. If Harold Pollack is doing that, walking around the University of Chicago, I figure that it's just another colleague that was playing with his iPhone and stepped on my foot — and I ignore it and move on. If I'm a 17-year-old kid in Fenger High School, I can't afford to have people punk me. I got to get home. And I got a nice jacket, and my mom has told me that if somebody comes and takes my jacket, she can't get me another one. So when somebody does something like that, I might respond in a way that to the middle-aged white professor seems really excessive, but in the life of that kid is really human — there's an incentive to reacting really harshly.

Pollack emphasized that these kids are not in any way bad or evil. They have rational incentives for behaving in the way they do: In the tough environments they grow up in, sometimes it is important to fight.

But, Pollack explained, "What we want to tell them is, 'You may have to fight as a last resort. But you got to have other things in the toolkit that you go to first. And many of the situations where you might jump to escalate, you have more options, and the long-term consequences for you if you can avoid that confrontation are much better than if you react instinctively.'"

6) Eliminate blighted housing

One of the more unexpected ideas I heard from policy experts: Clean up and repair blighted buildings.

But it seems to work: A 2015 study from Branas, who's part of the Urban Health Lab, and other researchers found fixing up abandoned and vacant buildings in Philadelphia led to significant drops in overall crimes, total assaults, gun assaults, and nuisance crimes. There was no evidence that crime shifted to other areas, although there were signs that drug dealing, drug possession, and property crimes went up around remediated buildings. Still, net gains overall.

Branas characterized the findings as proof of a big gain for a pretty small investment.

"It makes the space appear cared for, and suddenly criminal activity doesn't want to happen there"

So what explains this? "It makes the space appear cared for, and suddenly criminal activity doesn't want to happen there," Branas said. "Also, the neighbors get more invested in the space and look after it — more of an informal policing mechanism."

Another potential explanation, according to Branas: Some would-be shooters may stash guns in vacant or abandoned spaces, since they want to avoid getting caught with illegal firearms. So when those vacant or abandoned spaces go away, they may decide to forego at least some guns — and may not be able to carry out some violence.

It's certainly one of the more exotic ideas I heard from researchers. But combined with the other proposals I heard from experts, it helps show that there are many varied policies lawmakers could embrace to combat crime and gun violence in the US — yet perhaps haven't to the extent that the evidence suggests they should.