Cherie Rhoades, 44, was arrested at the scene Thursday afternoon, the Modoc County Record reported. Police said she pulled out a gun at a meeting at the Cedarville Rancheria Tribal Office to discuss her eviction from the rancheria in northeastern California.
The victims were identified Friday as Rhoades' brother, Rurik Davis, 50, her nephew, Glenn Calonicco, 30, and niece, Angel Penn, 19. The fourth victim was Sheila Russo, 47, wife of a county sheriff's employee.
Police said she allegedly opened fire on the group, ran out of ammunition and grabbed a butcher knife from the office's kitchen.
Two people were wounded, one by gunfire and the other with the knife and both were in critical condition, Alturas Police Chief Ken Barnes said.
Barnes said Rhoades was transferred from the Modoc County Jail in Alturas to an undisclosed facility because of fears for her safety.
The Cedarville Rancheria is a federally recognized settlement of the Paiute tribe. Rancherias are small areas of land granted decades ago to California's remaining American Indian inhabitants.