Court hears of attacks on prostitutes

Three prostitutes were terrorised and two made to strip naked in a string of violent robberies in Adelaide, a court has heard.

In the two most serious attacks in 2014, two men and a youth aged 17 lured prostitutes into a car where they were threatened and forced to remove their clothes.

In one case the woman had a knife held to her throat and was told she would be buried alive before being forced into the boot of the car and driven to another location.

South Australian District Court Judge Gordon Barrett said while the youth was 17 at the time of the offending and was under the influence of an older man who was the instigator of the crimes, he was more than a passive participant.

"You physically took part in the attacks on the women," the judge said in sentencing the teenager on Wednesday.

"I can hardly overemphasise the seriousness of that offending."

The youth had pleaded guilty to numerous charges including two counts of aggravated serious criminal trespass and three counts of aggravated robbery, which all carried maximum sentences of life in jail.

But Judge Barrett imposed a head sentence of three years and nine months and said he found good reason to suspend the term, taking into account the youth's age and that he had an intellectual disability.

He placed the youth on a three-year good-behaviour bond and said a condition of that bond should include continued anger-management counselling.