Brothers William and Eric Siale suffered gunshot wounds during the alleged shooting at a barbershop on Marrickville Road in Marrickville about 1.50pm on July 7, 2023.
Both were treated by paramedics before being taken to hospital, with one man suffering serious injuries.
A short time later, two burnt-out cars were found in Marrickville and Dulwich Hill, which were treated as linked.
Crime scenes were set up and an investigation headed by Strike Force Orsino detectives was launched.
Police have previously charged 14 men who remain before the courts.
Officers yesterday morning arrested a 23-year-old man during a raid of a property at Edmondson Park in south-west Sydney.
He was charged with shooting with intent to murder, participating in a criminal group, supplying a prohibited drug and failing to comply with an order to give digital evidence.
He is due to appear in court today.
