KILLER drivers, drug dealers, serial burglars and people caught with child pornography could escape prison under plans to cut out short sentences, a judge has told MSPs.

Lord Turnbull, a former chair of the Scottish Sentencing Council, told Holyrood’s Justice Committee the changes could affect those currently sentenced to 18 months in jail.

There is already a presumption against prison sentences of less than three months, with JPs and sheriffs having to justify a decision to send someone to jail for a few weeks.

The SNP Government wants to extend the presumption from three months to 12 to reduce reoffending.

However the Sentencing Council warned the longer presumption could affect sentences up to 18 months as a discount of up to a third is applied to early guilty pleas.

This could bring the sentence down to 12 months, within range of the presumption, resulting in an offender getting a community sentence instead of prison, it said.

After Tory MSP Liam Kerr raised the issue, Lord Turnbull confirmed a series of offenders could benefit from the discount, but added sheriffs may well take that into account.

After the three-month presumption was introduced, sheriffs set more four-month prison terms to get around it, an unintended consequence called “up-tariffing”.

Lord Turnbull said courts must have prison as a “final sanction”, otherwise offenders on community sentences could breach them with impunity and see them as “voluntary”, undermining public confidence in the system.

He said a 12-month presumption could cover assaults against the police, ambulance and fire crews.

Among the “more serious offences” attracting a 15 to 18 month jail term which could be shortened by a guilty plea, he listed “causing death by careless driving, causing death while driving disqualified, possession of indecent photographs of children, possibly even distribution of lower category images, possession of offensive knives or weapons, assaults... some drugs supply charges, sexual offences, charges of multiple housebreaking.”

However he added: “We’ll have to wait and see what individual sentencers decide in that situation. But I would have thought that if the sentencer starts off with the conclusion that a sentence in the region of 15 to 18 months is the only appropriate sentence, he’s quite unlikely to change his mind.

Yes, he’ll think again, but is he likely to come to a different conclusion? I’m not so sure.”

Earlier, MSPs heard the plans could leave councils struggling to cope with more community sentences, while academics questioned if the change would reduce reoffending rates.

Criminologist Dr Cyrus Tata of Strathclyde University said the SNP government’s claim that the presumption against three-month sentences had cut reoffending was “dodgy”, as it was based on a crude comparison between two very different kinds of offender.

Mr Kerr said: “Victims were already disgusted at the idea of scrapping sentences of less than a year.

“The fact this seems to be increasing to 18 months will compound that feeling that they’re being let down by a soft-touch justice system under the SNP.

“It’s also very concerning to hear that violent criminals who attack police, paramedics and fire-fighters could be let off the hook. The SNP needs to think again on this.

“It’s vital that the justice system keeps ordinary people safe, punishes crime and offers sufficient deterrent to those considering crime.

“The SNP’s proposals fail on every single one of those counts.”

A spokesperson for Justice Secretary Humza Yousaf said: “The presumption is not a ban - prison will always be the right place for the most serious offenders and those who pose a risk to the public.

“The presumption will only apply in cases where a court has reached a view that a sentence of 12 months or less may be appropriate having taken into account all relevant factors.”