REDDING, Calif. -- A California woman abducted while jogging was branded by two female captors who kept their faces covered during the three weeks they held her, a sheriff said Wednesday in seeking the public's help to solve a crime that has riveted and unnerved the community.The Spanish-speaking suspects also kept the head of 34-year-old victim Sherri Papini covered at times, limiting her ability to provide descriptions so authorities could draw sketches, Shasta County Sheriff Tom Bosenko said at a news conference.The abductors may have been trying to humiliate and wear down Papini by branding her and cutting off her long hair, Bosenko told "Good Morning America." "I would think that that was some sort of either an exertion of power and control and/or maybe some type of message," he said, emphasizing that the brand was a message, not a symbol.At the news conference later in the day, the sheriff said authorities still lack a motive for the abduction."We do not know if she was a specific target or if this was a random abduction," he said.Bosenko declined comment on where Papini had been branded or where she was held by her captors.He said he is not sharing all the details of the investigation and asked for the public's help in finding the two women, saying authorities are trying to do a sketch of the suspects based on Papini's limited recollections.Papini told investigators the younger woman had long curly hair, thin eyebrows and a thick accent. The older suspect had straight black hair with some gray and thick eyebrows.The sheriff warned residents to remain cautious until the suspects are identified.Papini, the mother of two small children, disappeared while jogging Nov. 2 near her home in Redding, about 140 miles north of Sacramento. She was released near Interstate 5.Her husband Keith Papini has said his wife was covered with bruises and burns and was chained at the waist and wrists when she was found.In a written statement Tuesday to "Good Morning America," he also addressed social media chatter doubting his wife's story of abduction and assault."Rumors, assumptions, lies, and hate have been both exhausting and disgusting," he wrote.The sheriff has said the case is puzzling for a number of reasons, including motive. He said no ransom demand was made and the Papinis are of modest means.Bosenko told the AP on Monday that investigators have no reason to doubt the harrowing tale told by Sherri Papini.Keith Papini said his wife weighed just 87 pounds and the bridge of her nose was broken when she was tossed from a vehicle along the interstate with her hands restrained and a bag over her head.Bosenko said Sherri Papini was unable to recall any details about her abduction when first questioned soon after being found.He said victims of traumatic experiences sometimes suffer from memory loss regarding the events.