The infant daughter of a 19-year-old woman who was among four people shot to death last week was found unharmed in her mother's apartment, police said Monday.
Investigators have ruled out murder-suicide in the shooting deaths of 19-year-old Sabrina Zephier, her 13-year-old brother, her mother and her mother's boyfriend, Minot Police Chief Jeff Balentine told The Associated Press.
Sabrina Zephier was found slain at an apartment Friday afternoon, but her infant daughter was unharmed and placed in protective custody, Balentine said. Police gave no reason for not disclosing that the child was found unharmed.
Sabrina Zephier's mother, 38-year-old Jolene Zephier; brother, Dylan, and Jolene Zephier's 22-year-old boyfriend, Jeremy Longie, were found slain in a Minot mobile home less than an hour after her body was found.
The Zephiers were members of South Dakota's Yankton Sioux Tribe.
Balentine said a "person of interest" has been interviewed in the case but no arrests have been made and investigators have not ruled out the possibility of more than one killer. He would not comment on a potential motive for the slayings that authorities believe are related.
Balentine earlier said the killings were not a case of "a gunman running amok."
Balentine said police are asking anyone who noticed suspicious activity or vehicles in the area of the killings early Friday to notify them.
Police were "re-interviewing" the victims' family members and others on Monday. Balentine said investigators also were studying surveillance video from area businesses to see if the victims had been seen with others on the day of the killings.
The victims' bodies were sent to Bismarck on Monday for autopsy, Balentine said.
The killings have alarmed residents in the town of about 36,000, about 100 miles north of Bismarck.
Minot Mayor Curt Zimbelman said Monday that the killings have resonated in his city, which has had five homicides since 2006 and just one all of last year.
"This definitely sent a shockwave through a community the size of ours, and most any city, I would guess. You just never know when it's your city," he told the AP.
North Dakota has averaged about 11 homicides annually in recent years, including 11 in 2010, the North Dakota Attorney General's office said.
Charges have been filed in all but one of those five Minot homicides, that of college student Anita Knutson, who was found stabbed to death in her apartment in 2007. A billboard of her likeness asking for information stands at the city limits, not far from Sabrina Zephier's apartment.