A recent wave of new policies and ballot measures makes it clear: Many politicians across the country think crime is out-of-control and tougher laws will help fix the problem.

From Louisiana to California, efforts to increase criminal penalties and give more power to police have made it on the books as politicians say they want to make their streets safer. Most Americans (58%), meanwhile, now think the country is not tough enough on crime, a reversal from just a few years earlier (41%), according to public opinion polling from Gallup.

The most recent wave of laws extend to even liberal enclaves like San Francisco, a marked turn from reforms passed years ago in the wake of George Floyd's murder, which sparked a mass awakening to the inequities of the criminal justice system.

Efforts to crack down on crime, commonly called "tough-on-crime" laws, have been studied for years and have been found to boost the number of people in jail, but there's little evidence that they're effective crime deterrent, experts say. That's in part because most people who commit crime aren’t thinking about the penalties for their actions.

Tough-on-crime laws attempt to solve crime by stigmatizing people who commit crimes rather than addressing the root causes, driving mass incarceration and disrupting families and communities while heavily impacting people of color, said Shari Stone-Mediatore, the cofounder of advocacy group Parole Illinois and a professor at Ohio-Wesleyan University.

“It’s not a productive way to deal with social problems” like drug addiction or unemployment, Stone-Mediatore said.

'A stunning turnabout':Voters and lawmakers across US move to reverse criminal justice reform

Because the latest wave of laws follow widespread criminal justice reforms, some experts note the new laws may not be as extreme as some past crime crackdowns.

"They're not going back to the way it was before," said Adam Gelb, President and CEO of the nonpartisan think tank Council on Criminal Justice. Many recent tough-on-crime laws are essentially rolling back some of the most controversial reforms, "rather than completely rejecting a balanced approach."

He also acknowledged that some policies that have popped up recently may be intended to send a message about crime tolerance rather than stop crime directly.

‘Restored law and order’: Crime rates prompting concern by politicians

Crime rates fluctuate based on innumerable factors, which the U.S. has seen throughout history, according to Jeffrey Bellin, a professor at the William & Mary Law School and the author of “Mass Incarceration Nation: How the United States Became Addicted to Prisons and Jails and How It Can Recover.”

National data on crime rates shows that while crime went up during the early years of the COVID-19 pandemic, it has mostly returned to pre-pandemic levels or below. FBI crime reports show that violent crimes in particular, which jumped in 2020, have come back down. In 2022, there was a 6.1% decrease in murder and non-negligent manslaughter. Rape decreased 5.4% and aggravated assault dropped 1.1%, the data shows. 

Yet robbery increased 1.3%. Property crimes overall increased 7.1% in 2022, with motor vehicle thefts showing the biggest increase at 10.9%. Carjackings increased 8.1% from 2021, including those that led to injury.

“The COVID pandemic was such a shock to the system that it created all sorts of distortions, not just in terms of how people were behaving,” but also in how policing of communities was carried out, Bellin said.

In Louisiana, which just overhauled its criminal justice system and reversed previous efforts at reform in a special session, crime rates have followed a similar pattern, but the state has had one of the highest homicide rates in the country in recent years.

“(C)riminals have been thriving while our law enforcement officers are more demoralized than ever,” Louisiana Gov. Jeff Landry and Louisiana Sen. John Kennedy, both Republicans, said in an opinion article published by USA TODAY’s Network in Louisiana.

“With this Special Session, the Louisiana Legislature restored law and order and put criminals on notice that they will face punishments for their crimes,” they said.

Among the legislation passed: laws that will treat all 17-year-olds who commit crimes as adults, harsher penalties for carjackings and a minimum of 25 years in jail in cases where someone distributes fentanyl in a way that appeals to children, such as the shape, color, taste or packaging design.

Meanwhile in California, San Francisco voted for two propositions that give police more leeway to pursue suspects in vehicles and expand the use of drones and surveillance cameras, and that require welfare recipients to undergo drug treatment. In Washington, D.C., the city council approved public safety measures including establishing “drug-free zones” to target drug-related loitering.

In Oregon, the first state to decriminalize illicit drugs three years ago, politicians have reinstated criminal penalties for possession of some drugs.

READ MORE:'A stunning turnabout': Voters and lawmakers across US move to reverse criminal justice reform

Low-level offenses often targeted in crime crackdowns

When elected officials want to crack down on crime rates, they often choose to implement harsher sentences for crimes, including lower-level offenses, leading to longer prison sentences and more people in prison. The hope is that keeping criminals off the streets will lessen the amount of crime that is committed, and deter others from committing crime. 

“Tough on crime in this country is a way of thinking about how to deal with social problems that became strongly articulated in the late 70s and 80s,” Stone-Mediatore said. “Since then, study after study has shown that it does not work.” 

A good example of a tough-on-crime approach is the U.S. war on drugs that saw a sharp increase in the number of people sent to prison for drug offenses starting in the 70s, Bellin said. Yet that didn’t reduce the availability of drugs or the number of people using them, Bellin said.

Tough-on-crime laws often target crimes that are easier for police to detect, like drug offenses, rather than the types of crimes that people most care about, like sexual violence and murder, Bellin said. 

When considering what effect tough-on-crime laws have, Bellin said, “what we really mean is tough on the people we catch.”

Want to prevent crime? Make people believe they will be caught, research suggests.

According to Stone-Mediatore and Bellin, research shows people care about getting caught and often have a warped sense of whether they will be.

But laws that increase prison sentences don’t inherently deter them, because the people potentially committing crimes may not know about what those new penalties are.

The National Institute of Justice, a body of the U.S. Department of Justice, found in a 2016 analysis of a wide body of research that: 

• The severity and length of punishment is a less effective deterrent than the certainty of being caught. Police can deter crime by increasing the perception that criminals will be caught. 
• A prison sentence for every person convicted of a crime is not effective at deterring crime. Rather, people who go to prison may learn more effective crime strategies while they’re in prison.
• Research doesn’t prove that the death penalty deters people from committing homicides. 

What can result in reduced violent crimes like murder is expanding law enforcement’s ability to investigate and prosecute those more serious crimes rather than focusing on lower-level crimes like drug offenses. 

“If it's likely that you'll get caught for committing a crime, you're less likely to commit the crime,” Bellin said, regardless of how stiff the penalty is.

Contributing: Kinsey Crowley, USA TODAY; The Associated Press