A former lord chief justice has called for an end to mandatory life sentences for murder.
Lord Woolf said life prison terms were handed down "too frequently" by the courts, and judges should be able to be "more precise" in the way they passed sentences.
A long-standing supporter of penal reform, he expressed concern that public demands for tougher punishments were driving up sentences, putting increasing strain on the prison system.
"The period murderers are now spending in prison has grown very substantially over the last 20 years," he told BBC Radio 4's The World At One.
"I think it is unfortunate that we give life sentences so frequently as we do. I would much rather have a situation where there are no mandatory life sentences.
"Sometimes a murder - it's still a murder - but it can be very much less serious than another murder.
"There may not be circumstances which excuse the killing, but there may be circumstances that describe a situation where a person was at the end of their tether, perhaps as a result of conduct for which they were in no way responsible.
"If you hit somebody intending to cause them serious injury and they fall down and hit their head (and die) and you didn't actually intend to murder them, then that is murder under our law. That has got to be dealt with now by a life sentence.
"I think we have got to be much more precise in our sentencing."
Lord Woolf, who led the inquiry into the 1990 Strangeways Prison riot, said sentencing "inflation" - in response to public pressure - meant more people were spending more time in jail, leaving the system struggling to cope.
"Unfortunately the public have been conditioned to expect what they regard as heavy sentences. They've got ideas in their mind of what they should be and they don't realise just what the effect is of sentences keeping on increasing," he said.
"I think we have got to give a message to the courts who actually do the sentencing that they should do what they can to keep inflation out of the situation."