CHICAGO (Reuters) - A man whose killing spree left a mother, her two teenage children, and her boyfriend shot to death in Minot, North Dakota, Friday afternoon, remained at large on Sunday, authorities said.
"This is a particularly chilling case," said Captain Dan Strandberg of the Minot Police Department.
"We have not made an arrest and we are working down our leads and evidence," he told Reuters by phone, adding that police have not established a motive.
"There are many things we still don't know."
Authorities say that on Friday a single shooter targeted and shot to death Sabrina Zephier, 19, who was found dead in a Minot apartment.
The three other victims -- Dylan Zephier, 13; Jolene Zephier, 38; and Jeremy Longie, 22 -- were killed in a Minot trailer park.
Sabrina and Dylan Zephier are Jolene Zephier's children; Strandberg identified Longie as Jolene's "romantic interest."
Minot, a city of 36,000, is located about 100 miles north of Bismarck.
(Reporting by Eric Johnson; Editing by Jerry Norton)
