The pair were convicted of murdering Luczak's four year-old son, Daniel, who was beaten, starved and tortured before his death.

On her Practical Ethics blog, Dr Roache notes that Luczak and Krezolek will receive the humane treatment that Daniel never did.

‘They will, for example, be fed and watered, housed in clean cells, allowed access to a toilet and washing facilities, allowed out of their cells for exercise and recreation,’ she writes.

Turning to human engineering as a possible solutions, Dr Roache looks at the idea of life span enhancements so that a life sentence in prison could last hundreds of years.

‘Dr Aubrey de Grey, co-founder of the anti-ageing Sens research foundation, believes that the first person to live to 1,000 years has already been born,’ she said.

‘The benefits of such radical lifespan enhancement are obvious - but it could also be harnessed to increase the severity of punishments’

As well as extending life, Dr Roache noted that there are a number of psychoactive drugs that distort people’s sense of time.

She said that society might not be far off developing a pill that could make someone feel like they were serving a 1,000-year sentence.

‘Of course, there is a widely held view that any amount of tinkering with a person’s brain is unacceptably invasive,’ she said. ‘But you might not need to interfere with the brain directly.’

Time distortion, for instance, is already a technique used in interrogation, where people are exposed to constant light, or unusual light changes, so that they can’t tell what time of day it is.

Another scenario being explored by the group is uploading the criminal's mind to a digital realm to speed up the 1,000 year sentence.

‘As the technology required to scan and map human brain processes improves, some believe it will one day be possible to upload human minds on to computers,’ Dr Roache said.

This means that with sufficient computer power, it would be possible to speed up the rate at which an uploaded mind runs.

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Prison firms could also soon develop drugs that make time pass slowly, making an inmate¿s sentence feel like an eternity

Similarly, uploading the mind of a convicted criminal and running it a million times faster than normal would enable the uploaded criminal to serve a 1,000 year sentence in eight-and-a-half hours.

‘This would, obviously, be much cheaper for the taxpayer than extending criminals’ lifespans to enable them to serve 1,000 years in real time,’ said Dr Roache.

If these technologies are developed, one crime that could ever justify eternal imprisonment was something that would endanger mankind.

‘Suppose there was some physics experiment that stood a decent chance of generating a black hole that could destroy the planet and all future generations,’ said Dr Roache.

'If someone deliberately set up an experiment like that, I could see that being the kind of supercrime that would justify an eternal sentence.’