If Mr Howard's proposals become law, will they prove any more successful? It seems unlikely. Mandatory sentences of imprisonment, the centrepiece of his plan, have been virtually unknown in English law (except for murder) since 1861, but there have been many experiments with mandatory sentences in the United States. A recent review of research into their effectiveness concludes that they always fail. Faced with the prospect of a sentence that seems unjust, prosecutors abandon cases or downgrade charges to offences that do not carry mandatory penalties, witnesses are reluctant to give evidence and juries are hesitant to convict.
Ironically, the Government recognised the problems inherent in mandatory sentences in their last White Paper on sentencing, published in 1990, which states unequivocally, "the Government rejects a rigid statutory framework, or a system of minimum or mandatory sentences for certain offences. This would make it more difficult to sentence justly in exceptional cases. It could also result in more acquittals by juries, with more guilty men and women going free unjustly."
Mr Howard's proposals go some way to acknowledging these problems. Courts will not be obliged to pass a life sentence on a second rapist or other second-time violent offenders if there are "genuinely exceptional circumstances". But who will decide what are exceptional circumstances? The judges. The judiciary will decide how much discretion to exercise, by interpreting the scope of this exception. If they place a broad interpretation on it, the mandatory element will be reduced, and courts will exercise customary discretion.
The prime objection to the proposed obligatory life sentence is that it will miss the real target. Mr Howard has identified the problem that an offender sentenced to a determinate sentence of imprisonment has to be released on a certain date, whether or not he is still dangerous. He was not the first to do so. A Committee on Mentally Abnormal Offenders, chaired by former Conservative Home Secretary Lord Butler, highlighted the same point 20 years ago. Their solution - a reviewable sentence - was better: it applied to a wider range of offences and was within the discretion of the courts. Mr Howard's scheme seems bound to require courts to pass life sentences where they are obviously inappropriate. A man was recently sentenced to five years for holding up a building society with a cucumber concealed in a plastic bag; if he does it again he will risk a life sentence. A man who persistently indecently assaults children, will not, as indecent assault is not punishable with life imprisonment.
Mandatory sentences for persistent burglars and drug traffickers are equally unpromising. In the case of drug traffickers they are simply redundant; courts at present work under clear judicial guidelines which result in severe sentences on first time drug traffickers. Long sentences on persistent burglars were authorised by legislation in 1908, 1948 and 1967; each time they failed.Under Mr Howard's scheme, a third-time burglar could be sentenced to the same sentence as a first-time rapist, or longer. The result will strike most people as unjust.
The writer is Reader in Criminal Justice at Cambridge University and editor of `Current Sentencing Practice'.