A Stoney Creek man who was one of three people who died in a Saturday evening triple fatality shot three people before turning the gun on himself, police say.

Hamilton Police say James Milroy, 37, shot 19-year-old Aerlaena Smith, his younger brother 32-year-old Michael Milroy and a 70-year-old woman before shooting himself. Smith and both Milroy brothers died. The 70-year-old, who neighbours say is their mother, survived and is in critical condition in hospital.

James Milroy and Smith were in a relationship, homicide investigators say.

The incident happened just before 7 p.m. on Saturday at 33 Valrose Dr.

Neighbour Burim Bajramali said on Sunday that he heard the sound of two gunshots, fired in quick succession, coming from inside the house next to his, 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.

Neighbours had already told reporters the family living in the home included Gina Milroy and her two sons, James and Michael.

Gina and one of the sons were wheeled out by paramedics on Saturday evening, Bajramali said. Both were wearing oxygen masks, covering their mouth and nose.

Jan Zadlo, who lives across the street, described Gina Milroy as a hard worker who worked at a Tim Hortons on Centennial Parkway, near Barton Street.

Zadlo moved into his home in 1989 and said he remembered Michael Milroy cruising up and down the street on his roller blades when he was a young kid.

The shooting was a shock to the community, he said.​