State attorney-general, Kyam Maher, will introduce a bill to parliament this week to punish adults with 15 years' jail if they recruit people under 18 to engage in criminal activity.

If the crime the child is incited to perform carries a maximum sentence greater than 15 years, the adult would be exposed to the greater of the two penalties.

Mr Maher said the law change follows responses to a discussion paper proposing to raise the age of criminal responsibility in SA, and not in response to any specific event or a rise in youth crime.

"If you're an adult and you're recruiting children, particularly young children, to commit crimes, then you ought to face very severe punishments," he told ABC Radio on Wednesday.

Similar offences have already been implemented in other states, with Victoria imposing a maximum penalty of 10 years in jail.

A carve-out means the offence will only apply to adults over 21, to prevent older teens who associate with children of a similar age being captured by the legislation.

For example, if a 19-year-old is part of a group that also includes 17-year-olds, they will be exempt from the offence.

The offence will also only apply to children who commit a major indictable offence - crimes that carry a maximum penalty of at least five years in prison.

This means common crimes such as shoplifting, which has jumped by almost a third over the past 12 months, will not be captured by the new law unless the value of goods stolen exceeds $30,000.

Opposition Leader David Speirs is supportive of "the spirit of the legislation", although he hasn't had time to scrutinise the detail.

"At this stage, it sounds like it's a good piece of legislation and that direction sounds like one that the government should be headed in," he told reporters.

Australian Associated Press