(CNN) -- A Long Island, New York, corrections officer turned her automatic 9mm weapon on her estranged partner and then on relatives Wednesday morning, killing two people and injuring another, Nassau County police said.
Police said Kim Wolfe, a 43-year-old jail guard, was arrested later Wednesday and is expected be arraigned on Thursday.
She is accused of shooting 45-year-old Stacie Williams multiple times, then driving to her grandparents home where she killed her uncle, wounded her grandfather and abducted her niece, police said.
Motives for the shootings were unclear, police said, but they added that Wolfe and Williams had agreed to meet outside the Nassau University Medical Center in East Meadow, Long Island, where Williams worked the night shift.
"The two women had been in a domestic relationship but they were estranged. It's unclear what the meeting was about," said Detective Vincent Rodriguez of the Nassau County Police Department.
Police said after the initial shooting, Wolfe drove from to her grandparents' home in Hempstead, about four miles away, where she had an argument with her grandfather "about insurance papers." When Wolfe's 56-year-old uncle intervened, he was shot multiple times and killed, police said.
Wolfe shot her grandfather in the leg, wounding him, and then abducted her niece and fled the scene, according to police.
"She had insurance papers she wanted the family to sign." said Rodriguez, adding, "I think it had something to do with her estate, though it's still very early in the investigation."
Police arrested Wolfe later Wednesday morning as she was driving down a residential street in Hempstead with her niece. Police Officer Michael Aronsen of the Nassau Police Department said Wolfe was armed but surrendered peacefully. Her niece was unharmed.
Williams had worked as a nurse's aide in the maternity ward for the Nassau County Medical Center for 23 years, according to Shelley Lotenberg, a hospital spokeswoman.
CNN's Rosa Barney contributed to this report.