TIMOTHY JACKSON stole a jacket from a shop in New Orleans in 1996. When followed by a detective, he dropped it and tried to walk away. He was caught, convicted and sentenced to life imprisonment with no chance of parole. “I’m locked up like I killed someone,” he told the New Orleans Times-Picayune. Actually, his punishment is harsher than that. Even Charles Manson, a multiple murderer, is allowed to apply for parole. Mr Manson is unlikely ever to get it, but at least he receives a hearing. Mr Jackson, a petty thief, does not.

His punishment is harsh because he is a recidivist in a state with mandatory tough sentences for habitual criminals. Under Louisiana’s “four-strikes” law, his two previous convictions for stealing from cars and one juvenile conviction for robbery gave the judge no choice but to throw away the key.

Forget them not

No one knows how many non-violent criminals are serving life without parole in America, but the American Civil Liberties Union (ACLU) has counted 3,278 in the federal system and the states that release statistics (see article). The true number is probably higher. And this does not include prisoners serving sentences that, while not technically “life without parole”, are so long that it makes little difference, such as Bernie Madoff’s 150-year penalty for a massive financial fraud.

Some criminals should be locked up for ever. It would be absurdly risky to release a murderer like Mr Manson, who shows no remorse and still describes himself as dangerous. For those who oppose the death penalty (as The Economist does), “whole life” sentences are a useful alternative. Many voters want murderers to be executed to make sure they never kill again; support for capital punishment weakens when the option of permanent incarceration is available.

But there is no way to justify oubliettes for shoplifters. Judges who are allowed to use their discretion hardly ever condemn non-violent criminals to life without parole. In the ACLU’s sample, 83% of such sentences were the result of mandatory-sentencing laws. Most (79%) were for drug offences. Some of the criminals involved were kingpins, but others were low-level couriers or clueless addicts caught up in big drug busts. (Key members of a drug gang can often trade information for lighter sentences; peripheral figures typically know too little to do the same.) The drug crimes that trigger life without parole can be as trivial as owning a crack pipe or a bottle cap with a trace of heroin on it. The non-drug crimes can be just as ludicrous: trying to cash a stolen cheque; siphoning petrol from a truck; threatening a cop while handcuffed.

The inmates of the American oubliette are typically poor and none too bright. Many had bad lawyers. Most are black. Those who receive life without parole for non-violent crimes are even more likely to be black than prisoners in general: 65% of the national total and 91% of those in Louisiana, estimates the ACLU. But the problem with the system is not racial bias; applying such draconian, hope-crushing sentences to non-violent offenders of any race is cruel and pointless.

The main purpose of prison is to reduce crime, by keeping criminals off the streets and deterring others from following their example. It makes sense to lock violent offenders away, especially while they are young, fit and impulsive, and to treat habitual criminals more severely than novices. But keeping petty thieves in cells until they die of old age yields negligible benefits at ruinous expense. A year behind bars can cost more than tuition at Harvard; the human cost is unknowable.

In August Eric Holder, Barack Obama’s attorney-general, admitted that America locks up too many people for far too long: with a twentieth of the world’s population, it has a quarter of its prisoners. Mr Holder promised to tell federal prosecutors to seek shorter sentences for non-violent offenders with no ties to organised crime. That was a good start, but no more.

Congress and state legislatures should scrap mandatory sentencing and let judges judge. America should favour shorter sentences coupled with greater efforts to rehabilitate wrongdoers—electronic ankle tags are cheaper and kinder than incarceration. Ideally, more states would join the 20 that have decriminalised marijuana, as a step towards treating addicts instead of punishing them. At the very least, Mr Obama and the state governors should use their clemency powers to reduce the sentences of those now locked up for ever for non-violent crimes. Mr Jackson’s sister told the ACLU: “It’s like he don’t even exist no more.” But he does, and his punishment disgraces every American official who has colluded in it.