Warren Alan Storing, 45, is being held without bail in the Sonoma County jail, Rohnert Park police Sgt. Joe Ferronato said.
Police say the victim, a 55-year-old woman, was about to fall asleep at a homeless encampment along a creek behind the Motel 6 at 6145 Commerce Blvd. when she was stabbed around 10:30 p.m. Sunday, Ferronato said. People in the area heard screaming and called police.
The woman suffered multiple stab wounds to her upper torso and was listed in critical but stable condition at Santa Rosa Memorial Hospital, Ferronato said.
Police have not recovered a weapon and do not know the motive, Ferronato said.
The woman and Storing, described by police as a drifter who has a mailing address in San Francisco, are acquaintances and had encountered each other over the past several days, Ferronato said.
Storing had been in Rohnert Park for five or six days, Ferronato said.