Police are unfairly criticized as heavy-handed and long prison sentences are reserved for hardened criminals, says a new book that takes aim at liberal calls to empty prisons and defund the police.

Author Rafael Mangual says his study, Criminal (In)Justice, debunks ‘dominant narratives’ that ‘black and brown men’ unduly suffer at the hands of police and a criminal justice system that is stacked against them.

It runs counter to dozens of studies that have found that black people disproportionately suffer from police stops, searches and deaths in custody. A recent opinion poll found that 89 percent of Americans wanted police reforms.

Mangual, however, says he has crunched the numbers and found a ‘glaring incongruity between what the harshest critics of law enforcement were saying — about imprisonment and police use of force — and reality’.

‘A sober examination of the data on who goes to prison reveals that lengthy terms of incarceration are reserved for chronic, violent offenders who’ve already been given multiple “second chances”,’ said Mangual.

The author, who was raised in Brooklyn and Long Island, says 60.1 percent of prisoners in state-run centers were behind bars for violent or weapons offenses — not low-level or non-violent criminals.

They are very often repeat offenders, he added. Some 36 percent of violent convicted felons were on parole, probation, or pretrial release at the time of their offenses; and 80 percent of state prisoners commit new crimes within a decade of their release.

Crime, says Mangual, is ‘hyper-concentrated’ in run-down parts of towns and cities that warrant police attention. In New York, where rising crime rates alarm residents, about half the city’s violent crimes are concentrated in only 4 percent of its streets, he says.

The author, a fellow at the right-leaning Manhattan Institute think tank, said the examples of heavy-handed policing were overblown, and that moves to cut funding or lift police immunity would do little to reduce the use of force.

He cites data from North Carolina, Louisiana and Arizona that found officers used force in only 0.78 percent of arrests. Other research from 2018 showed police fired weapons in only 0.03 percent of arrests, he added.

The book has won plaudits from Republican heavyweights like Arkansas Senator Tom Cotton and former Attorney General William Barr, as well as Bill Bratton, New York’s former police commissioner.

Cotton said it countered ‘soft-on-crime policies’ from the ‘left’s jailbreak movement’. Barr called it a ‘powerful case’ against dropping the law-and-order approach that helped end America’s crime wave in the early 1990s.

The book comes amid widespread criticism of cops using deadly force on unarmed black men, notably George Floyd in Minneapolis in May 2020, which stoked huge Black Lives Matter protests and calls to defund police forces.

Two former Minneapolis Police officers — J. Alexander Kueng and Tou Thao — were on Wednesday each sentenced to at least three years in prison, after being convicted of federal charges of failing to intervene as Floyd was restrained.

Floyd’s death was a ‘tragedy and a murder’, Mangual told DailyMail.com.

‘Legal police use of force is extremely rare, illegal police use of force is rarer still —that doesn’t mean it doesn’t happen and is not a problem. But how do we tackle it in a way that doesn’t impose the serious cost of diminished public safety on communities that cannot afford it?’

Critics have long bashed the justice system for disproportionately caging minorities — black people are imprisoned at nearly five times the rate of whites, while Latinos are imprisoned at 1.3 times the rate of whites, according to The Sentencing Project.

Half of Americans polled by Gallup earlier this year called for ‘major changes’ to policing, while a further 39 percent wanted minor changes. Only 11 percent said there was no need for change.

Black Americans felt more strongly, with 72 percent seeking broad reforms.

Still, there has also been a blowback against soft-on-crime policies as rates of homicide and violent crime rose during the Covid-19 pandemic, stoking fears that Los Angeles, New York and other cities would revert to the crime-ridden 1990s.

Voters in San Francisco last month ousted in a recall election a progressive district attorney who was blamed for a spike in gun violence and other crimes. Likewise, New Yorkers last year elected former cop Eric Adams, a tough-on-crime Democrat, as mayor.