SA court urges cops to speed up DNA tests

A magistrate has urged prosecutors to speed up the processing of DNA evidence in a South Australian cold case after three men and a woman were charged over the murder.

Jayson Doelz was bashed and stabbed, and his body was found in a roadside ditch in Kersbrook in the Adelaide Hills in January 2012, but the four accused were only charged in September this year.

"Mr Prosecutor I invite you to do everything you can to prioritise the DNA material," magistrate Bob Harrap said on Tuesday when the quartet appeared in the Adelaide Magistates Court.

Mr Harrap urged prosectors to work swiftly on the case, noting the seriousness of the crime and the fact three men were in custody over it.

Mr Doelz was allegedly assaulted at a home in Parooka, in Adelaide's north, before being bundled into the boot of a car and driven to the Adelaide Hills.

He briefly escaped before he was killed at the side of the road, the court previously heard.

A Moonta man, a Northfield man and an Ingle Farm man, aged between 26 and 31, have all been charged with his murder.

An Ingle Farm woman, 28, has been charged with assisting the men. She is accused of helping to clean the house where Mr Doelz was first assaulted before he was kidnapped.

The identities of all four accused are suppressed.

A car linked to the murder was found in July this year buried five metres under a shed in the SA outback.

The case will return to court on February 10.