Allan Sjodin said two weeks of fruitless efforts to find his daughter would not stop him from looking for her Monday. "I haven't lost any energy," he said.
Police planned to review their progress Monday morning, but didn't plan additional searches of their own unless there is a new development.
"We're going to sit down and make sure we know where we're at, where we're going, and how we get there," Grand Forks Police Capt. Mike Kirby said.
Kirby denied police were giving up.
"No, I'm not prepared to say that we're giving up hope," he told CBS News Early Show National Correspondent Jon Frankel. "I mean, I've been in this business a long time and I understand the realities of a call like this, but by the same token Elizabeth Smart — I mean, anything could happen."
The teen-age Smart was abducted at knifepoint from her Utah home June 5, 2002, and then was found in good condition and her alleged kidnappers arrested nine months later.
Police believe the 22-year-old Pequot Lakes, Minn., woman was abducted from a shopping mall parking lot in Grand Forks. She has been missing since Nov. 22.
Alfonso Rodriguez Jr., 50, of Crookston, Minn., has been charged with kidnapping in the case. His attorney says Rodriguez told him he had nothing to do with Sjodin's disappearance.
Gerry Moreno, a police officer in Crookston, grew up with the Rodriguez family. He told Frankel even Rodriguez's own sister was worried that if released from prison he might hurt someone else. This past spring, he got a call from Ileana Rodriguez asking for help to keep her brother behind bars.
"I think she probably did have some fears," Moreno said.
Prosecutors are willing to unseal the evidence that led to Rodriguez's arrest. His attorney will announce Tuesday whether he wants the information made public.
Bob Heales, a private investigator working with Sjodin's relatives, said the family needed a day off Sunday to regain strength. Some relatives returned to Minnesota as others moved from a Grand Forks hotel where they had stayed.
"They were physically and emotionally at the end of their rope," he said Sunday. "It was a break, and we'll start fresh in the morning."
Heales said friends and family may target an area near Polk County, Minn., highlighted by a recent tip to a Web site devoted to Sjodin's case.
Mike Sjodin, 26, the missing woman's cousin, said he could barely stay awake after two weeks of nonstop searching, and said he had lost weight after hiking through snowy fields and raking out ditches looking for clues.
"Mentally, physically, emotionally, I needed to rest and get some more fuel," he said Sunday. "Eating and sleeping haven't been easy."
Allan Sjodin said taking a day off also was stressful.
"It's terrible to wait, wonder and worry," he said.
Heales said he feels like part of the Sjodin family after working so closely with relatives and friends. He is based in Denver, but has a home in Cross Lake, Minn., near the Sjodin family home in Pequot Lakes.
"I've known them for less than two weeks, and I feel like I've known them my whole life," he said. "To a lot of us, we'll be like family forever."
They continue to hope that Sjodin is being held alive somewhere, he said.
"I know she's out there," Mike Sjodin said.
Although the number of investigators has dropped recently, the search for Sjodin is still a priority as investigators quietly pore over leads, Kirby said.
"As we work through these, if we determine there needs to be another large-scale search, we'll coordinate that," Kirby said.
Kirby said authorities are still encouraging property owners to check fields and buildings for any clues.
"I'm surprised at the number of people who haven't done it, or didn't think of it," he said.
Alfonso Rodriguez faces a preliminary hearing Feb. 4, and arraignment on Feb. 6.