Proposed prison sentencing reforms will strike the right balance between punishment and rehabilitation, according to the justice minister.
Cathy Jamieson said she wants to tackle reoffending
Under the plans, criminals may still be freed half-way through their sentence.
Opposition MSPs have called for tougher proposals after it emerged that one of Kriss Donald's killers had been released early from jail.
However, Cathy Jamieson said prisoners would only be released after a safety assessment and under strict conditions.
She told BBC Radio Scotland's Good Morning Scotland programme that the new system aimed to prevent people from reoffending.
"There will be a two-part sentence where the judge will decide on how long a person should spend in custody, but also very importantly we will now ensure that anyone serving a sentence of more than 15 days will also serve part of their sentence in the community and they will be under supervision for that," she said.
However, opposition parties said the new system did not go far enough as it would not end early release.
Scottish Conservative leader Annabel Goldie said: "Currently, an offender sentenced to six years will spend four years in jail.
"Under the first minister's proposed system, that offender could spend three years in jail.
"How is that 'a completely new way of dealing with sentencing' and how on earth will it make Scotland a safer place?"
However, Ms Jamieson said there would be no automatic early release from the custodial part of a sentence and criminals would be released on licence.
She said: "What will happen is a judge might decide that someone will spend a year in prison and they would then perhaps spend a year in the community.
"But it will be possible under the new scheme, if that person doesn't co-operate or stick to their programmes while they are in prison and they continue to pose a risk to the public, for that person to be kept in custody longer.
"That's a very substantial shift from the current system whereby a person serving a sentence of less than four years simply walks out of the prison gates after they've served 50% of their sentence with no follow-up in the community necessarily in place and no opportunity to bring them back into prison if they don't comply."
Ms Goldie dismissed the proposals and said: "The best place for supervision and the safest place to ensure that somebody does not reoffend is not out on licence in the community, it is in jail."
The Scottish National Party said if elected it would create a sentencing council to set out general sentencing guidelines for sheriffs and judges.
Justice spokesman Kenny MacAskill said a council would ensure transparency and consistency in sentencing.
The Scottish Executive's sentencing bill is currently before a Holyrood justice committee.
It emerged last week that Imran Shahid, one of the men convicted of the racially motivated murder of teenager Kriss had been released early from prison while serving a 30-month sentence in February 2003 for assault to danger of life and dangerous driving.
Kriss Donald was abducted on 15 March, 2004, from Pollokshields in Glasgow. He was later stabbed and set on fire.
His body was found by the Clyde Walkway in the east end of the city.
Imran Shahid, 29, Faisal Mushtaq, 27, and Zeeshan Shahid, 28, were convicted of murder and given mandatory life sentences.
Imran Shahid must serve a minimum of 25 years, Zeeshan Shahid, 23 years minimum and Mushtaq, at least 22 years.