Sheriff's deputies have arrested a Sonoma County woman who ran to a neighbor's front door clutching a knife in bloody hands and said she had killed her mother, authorities said Monday.

The neighbor told deputies that Julia Franzen knocked on the door on the 7900 block of Tocchini Street north of Sebastopol about 8:05 a.m. Monday. Franzen, 24, told the neighbor she had just killed someone, then ran back into her house, said Lt. Steve Brown, a sheriff's spokesman.

After deputies arrived, Franzen came out unarmed but with blood on her hands and clothes, Brown said.

Officers handcuffed Franzen, then entered the home in the unincorporated area and found her mother, Nancy Franzen, 59, on a bedroom floor. She had been stabbed repeatedly, Brown said.