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SYRACUSE, N.Y. (AP) — Two sisters-in-law have been released from the hospital after suffering critical injuries during a brutal attack near Glacier National Park in which two members of their family were shot and killed.

Christy Siau, 40, of the Syracuse, N.Y. area, was shot in the July 17 attack on Montana’s Blackfeet Indian Reservation and her 18-month-old daughter McKenzie and husband David were killed, according to authorities. Christina Siau, 30, of East Glacier Park, was stabbed before managing to kill the assailant.

The sisters-in-law were released from a Montana hospital Tuesday, the Siau family’s pastor, Dan Werthman, told the Syracuse Post-Standard.

Authorities say a Montana man, Derick Amos Madden, plowed into the family with his pickup truck as they were walking along a sidewalk in the small tourist town of East Glacier Park, then shot three of them with a shotgun. McKenzie was shot as her mother tried to run away with the toddler in her arms, according to Glacier County officials.

Madden ran out of ammunition and attacked Christina Siau with a knife but she fought back and killed him, authorities said.

Two other children of David and Christy Siau were present but not injured.

Authorities have not released a motive but said Madden, originally of Goldsby, Oklahoma, had mental health issues and a prior relationship with Christina Siau.