BILLINGS, Mont. (AP) - A man drove his pickup truck into a family as they walked in a tourist village bordering Glacier National Park and opened fire with a shotgun, killing one man and mortally wounding a toddler who was in her mother's arms before the mother's sister-in-law managed to kill the assailant after he ran out of ammunition, authorities said.
Killed in the weekend attack on the Blackfeet Indian Reservation in northwestern Montana were David Siau, 39, of Syracuse, New York, and Siau's 18-month-old daughter, McKenzie.
The assailant, Derick Amos Madden, 37, had been in a prior relationship with the woman who killed him and had mental health issues, the Glacier County Sheriff’s Office said Tuesday. Authorities did not say how he was killed.
Madden plowed his Toyota Tacoma into the Siau family just before 9 p.m. Sunday as they walked along road in the small town of East Glacier Park, hitting some of them before crashing into a tree, the sheriff's office said.
Madden got out and shot and killed David Siau and mortally wounded McKenzie. The young girl was being held by her mother, Christy Siau, 40, who was shot and wounded.
Madden then ran out of ammunition and used a knife to attack the sister-in-law, Christina Siau, 30, said Capt. Tom Seifert with the Glacier County Sheriff's Office.
But the woman fought back and fatally wounded Madden, who authorities said died at the scene. Seifert declined to say how Siau killed him.
Two other children of David and Christy Siau were present but managed to run away and were not injured.
McKenzie Siau was pronounced dead at the Indian Health Service hospital in Browning. Christy and Christina Siau suffered critical injuries and were flown to another hospital with a higher level of care.
Authorities were still trying to determine if Madden, originally of Goldsby, Oklahoma, had the shotgun legally.
The sheriff’s office described it as an "isolated...incident with a clear nexus between the victims and Madden" and said the investigation was ongoing. It was not clear what provoked Sunday’s attack beyond the prior relationship between Madden and Christina Siau.
Local authorities did not know of any previous interactions that Madden had with law enforcement. He had been working in East Glacier Park, a town of about 300 year-round residents bordering Glacier National Park that gets throngs of summer tourists.
Christina Siau was originally from New York and had been living in East Glacier Park. Her relatives were visiting, Seifert said.
Christy Siau was a former bookkeeper for the American Baptist Churches of New York State, according to a social media postings by the organization. She was described as "a long time and beloved member" of the organization's staff in a statement from Executive Minister Rev. James Kelsey.
Christy and David Siau were also active in the First Baptist Church of Hoosick Falls, New York, Kelsey said.