A woman will appear before court accused of assisting a teen after he allegedly shot and killed a man.

Joshua Macdonald, 40, was allegedly shot outside of a home on Bruce St in Merrylands West, Western Sydney, about 3.15pm on September 2.

WATCH THE VIDEO ABOVE: Second arrest in alleged mistaken identity killing

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Despite the best efforts of paramedics, Macdonald died at the scene. Police believe he was mistakenly killed in a botched gangland hit.

CCTV footage from nearby shows a car driving up to and stopping in front of the home before a gunman fired several shots through the rear window.

Two men, aged 18 and 19, were arrested about 30km south-west from where Macdonald was killed in West Hoxton on September 11.

Police allege a drone uncovered during investigations implicated the 18-year-old as the alleged shooter.

A 28-year-old woman has been charged during ongoing investigations into the alleged mistaken identity murder of 40-year-old Joshua Macdonald. Credit: 7NEWS

He was charged with murder and participating in a criminal group and remains in custody awaiting further court proceedings.

The 19-year-old was also charged with participating in a criminal group and driving while his licence was suspended.

He was granted bail and is expected to appear before Liverpool Local Court on September 24.

A week after the teenagers were arrested, police executed a search warrant at a unit in Wollongong on Friday and arrested a 28-year-old woman.

She was charged with allegedly being an accessory after the fact to murder, participating in a criminal group and failing to comply with a digital evidence access order.

Police will allege the woman provided surveillance for the gunman to make their escape from the Western Sydney crime scene. Credit: 7NEWS

She is expected to appear before Bail Division Local Court on Saturday, when police will allege she provided surveillance for the gunman to assist with their escape from the scene.

Investigations under Strike Force Haleno remain ongoing, and anyone with information has been urged to contact Crime Stoppers.