Oliver Conroy, 27, was allegedly assaulted and carjacked in the inner Brisbane suburb of Kelvin Grove about 10.30pm on July 24.
Charges against seven teenagers, including two girls aged 14 and 15, were upgraded after Mr Conroy died almost two weeks later.
They face life sentences under controversial "adult crime, adult time" laws introduced by Queensland's Liberal National government.
Solicitors for six of the teens faced Brisbane Magistrates Court on Monday in response to police forensic procedure applications to take DNA samples from the accused.
The samples were needed to help establish which of the teens faced a strong enough case against them to proceed to trial, prosecutor Liam Crowley told the court.
"The DNA may tend to disprove or prove the child was involved in the offences," Mr Crowley said.
One of the applications sought DNA samples to test against material that had been transferred onto Mr Conroy during the alleged assault.
Another application sought to match defendants to a car and to blood-stained footwear.
One of the children's lawyers opposed the application on the grounds it contained clerical errors and was not specific enough in the reasons for collecting his 16-year-old client's DNA.
The application referred to two residential addresses that were unrelated to the boy, Magistrate Lewis Shillito was told.
"It undermines the reliability of the document," lawyer Alexander Ralston Jones said.
"Where do these addresses come from? It undermines credibility."
None of the teens was required to appear but a mother of the accused attended court when their child's application was heard.
Solicitors for five other teens said they opposed the DNA application and sought an adjournment.
The magistrate said he shared Mr Jones's concerns and adjourned all six applications to August 31.
"Given the delay to DNA testing, I imagine this is not urgent?" Mr Shillito asked.
The prosecution responded it would prefer any DNA analysis to be complete before any of the teens applied for bail.
"A bail application might involve questioning the strength of the case," Mr Crowley said.
The seven teens - five boys aged 15 to 17 and two girls aged 14 and 15 - were remanded in custody.
They were previously charged with assaulting Mr Conroy and stealing his hybrid ute.
They are among 11 juveniles charged with murder under new Queensland laws.
If convicted, they face mandatory life sentences with a minimum of 20 years before parole under "adult crime, adult time" laws introduced by Queensland's LNP government.
Police have appealed for dashcam footage from the Kelvin Grove area.
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