Susan Powell, a 28-year-old mother of two young children, was reported missing Dec. 7, when she didn't show up for work. She was last seen a day earlier.
"Every lead we've been offered so far would leave us to believe this is out of character (for Susan) and thus suspect foul play is involved," West Valley City Asst. Police Chief Craig Black said Wednesday.
He said her husband, Josh Powell, has not been named a suspect, but investigators are highly interested in him.
"Josh's unusual lack of cooperation for a husband looking for his wife with the police department, you know, it certainly causes us to ask questions as to why would he do things to exclude the resources that we can bring to the table to find Susan," Black said.
"If you're the spouse of someone who goes missing under strange circumstances," says CBS News legal analust Trent Copeland, "you really are the only person of interest at the initial time of the investigation."
Josh Powell said he went camping with their boys, ages 2 and 4, in subfreezing temperatures about 12:30 a.m. on Dec. 7 and returned in the evening. He says Susan Powell was alive, at home, when he left.
But Josh Powell has been uncooperative in providing any details that might explain what happened to his wife, Black said.
Among other things, Josh Powell hasn't specified where he went camping or where he was all day on Dec. 7, he said.
"That would be awesome if he would be willing to cooperate on that level and take us to his camp site," Black said.
Powell has told police he went camping in Simpson Springs on the historic Pony Express Trail in Utah's west desert - an area of thousands of square miles - that is now covered in snow.
Documents show Josh Powell filed for bankruptcy in recent years, with $200,000 in debt. And published reports suggest the couple had marital problems, with one friend telling the Salt Lake Tribune, "Susan did not want to give up on her marriage."
"It's not surprising," Copeland says, "that friends would now share this with the police and the police are now going to use that as part of their investigation."
Josh Powell did provide a DNA sample to police Tuesday, as did several other family members.
Josh Powell's attorney, Scott Williams, a defense attorney who often defends high-profile clients, described the DNA testing as routine in such cases.
Williams disputed allegations made by police that his client had been uncooperative.
"Despite our continued invitation to be contacted with questions we received no contact from the police today (Wednesday) and as to the nature of prior information, we have answered all questions posed to us since Monday morning," he said. "Josh continues to favor attention on finding Susan and has been cooperating and providing information to that end."
Black reiterated that Josh Powell has given them little information of value.
"Any reason as to why she would've disappeared either of her own accord or because of some type of other foul play, he has not been cooperative with that," he said.
The Powell home was locked when officers initially arrived and they broke in, fearing the family had suffered from carbon monoxide poisoning.
Susan Powell's father, Charles Cox of Puyallup, Wash., said police found a wet spot in the home being dried by two fans, but police have declined to comment on that.
Investigators said there were no signs of forced entry at the home and they found Susan Powell's purse and cell phone there.
Susan Powell was last seen by someone other than her husband on Dec. 6 - a family friend who ate dinner with her at the couple's home following church.
Susan Powell's family hasn't given up on finding her, reports "Early Show" national correspondent Hattie Kauffman. They've created a Facebook page, and continue to distribute flyers.
The family has planned a news conference in the Seattle area on Thursday, according to a posting on the Facebook page.
They're also getting support from the father of Elizabeth Smart, who was kidnapped as a 14-year-old and held for nine months in 2002, in a famous case that also happened in Utah.
"If the family is forthcoming," he says, "and can get themselves cleared out of the way ... the sooner they're cleared, the quicker the rest of the investigation should go forward."
But Smart calls several aspects of the case "very suspect" with respect to Josh Powell.
Josh Powell's hobbies include gardening and landscaping, Kauffman notes.