A third person has been charged over the shooting death of Toowoomba man Thor Morgan earlier this year.
Police allege Mr Morgan, 25, was driving a car on Ruthven Street in Harlaxton when he was followed by two people in a stolen utility on March 15.
Police allege a firearm was discharged from the ute and Mr Morgan was shot in the head at about 2.50am.
Mr Morgan died from his injuries in Brisbane's Princess Alexandra Hospital two months later on May 16.
Goondiwindi resident Tina Kathleen Hazard, 36, has been charged with one count each of murder, unlawful possession of weapons and unlawful use of a motor vehicle.
She appeared in the Toowoomba Magistrates Court today and has been remanded in custody to return to court in September.
Toowoomba Criminal Investigation Branch officer Heath McQueen said police believed other people were likely involved in the offence.
"The investigation is ongoing, we have no intentions of stopping," Detective Inspector McQueen said.
"They [other people involved] can look over their shoulder and they can continue to look over their shoulder for a very long time.
"We will continue until we have held everybody accountable that is involved in this offence."
Two other people have also been charged over Mr Morgan's death.
A 24-year-old man from Cambooya, south of Toowoomba, is in custody on charges of murder, arson of a motor vehicle, unlawful use of a motor vehicle, and unlawful possession of weapons.
A 24-year-old woman, who is charged with being an accessory after the fact of murder, is on bail.
Police also allege other stolen cars were involved in the incident; a grey station wagon, which had been stolen from a Newtown home in February, and a white SUV stolen from a Mount Lofty address in March.
The cars were later found burnt out — one in Felton and another in the Oakey area.
Police say there may be other people in the community who have knowledge about the incident.
Investigations are continuing.
