Central New York resident David Siau and his infant daughter were killed on Sunday in a brutal attack near Glacier National Park in Montana.
Police say 37-year-old suspect Derick Amos Madden intentionally drove a vehicle into a group of people walking alongside the roadway.
Madden reportedly crash the vehicle into a tree and exited the vehicle with a shotgun. He then began shooting at the group, which included the Siau family.
Just before 9 p.m. on July 17, police received reports of a male shooting at a female in East Glacier Park, a tiny village located nearby the national park, said the Glacier County Sheriff’s Office in a release on Tuesday.
The suspect Derick Amos Madden, 37, of Goldsby, Oklahoma shot and killed David Siau, 39, of Syracuse at the scene.
Police claim Madden kept shooting at victims who were running away. He wounded David’s wife Christy Siau, 40, who was carrying their 1-and-a-half-year-old daughter McKenzie in her arms. McKenzie later died as a result of wounds sustained during the attack.
Madden also attacked David’s sister Christina Siau, 30, of East Glacier Park, with a knife.
The GCSO says Christina fought for her life and fatally wounded Madden, who died at the scene. Christina and Madden had a prior relationship, a subsequent investigation revealed. Madden also had a history of mental health issues.
The Siau’s two young children were also present during the attack but escaped injury.
Christy and Christina were both flown to receive treatment for critical injuries.
The Sheriff’s Office says the attack was isolated to this incident with a clear connection between Madden and the victims. The investigation is ongoing.