A 27 year-old-man, arrested in connection with the murder of Malcolm McKeown in Waringstown, has been released.
Mr McKeown, who was 54, was shot up to six times in broad daylight at a petrol station on 19 August 2019.
His body was found slumped in his parked car by two teenage boys.
Police believe he was killed nearly two hours before his body was discovered.
The suspect was detained in Belfast on Wednesday and has since been released.