A 69-year-old woman believed to be the mother of a shooter who killed three people in Stoney Creek has died.

Sang Ju (Gina) Milroy died at Hamilton General Hospital early Wednesday from gunshot injuries from the April 16 incident, police say.

The shooting happened just before 7 p.m. on Saturday, April 16 at 33 Valrose Dr.

Police say James Milroy, 37, shot 19-year-old Aerlaena Smith, his younger brother Michael Milroy, aged 32, and Gina Milroy, before turning the gun on himself.

Smith and the Milroy brothers died at the scene, while Gina Milroy had been in critical condition.

Police say investigators are awaiting results from the Center of Forensic Service and the Ontario Coroners Office before concluding the investigation.

Neighbour Burim Bajramali said he heard the sound of two gunshots, fired in quick succession that Saturday, coming from inside the house next to his, located at 33 Valrose Dr., shortly after 6 p.m. Saturday.

The 33-year-old reacted by locking the door to his house, taking his wife and child to the basement, and listening to the sirens as the street filled with Hamilton police officers, he told CBC News.

"I was shaking. I was so scared," he said, standing outside his home on Sunday morning.