SALT LAKE CITY — The family of a Utah mother who has been missing for 10 days says they are saddened but not surprised that her husband has been named a person of interest in the investigation.

A friend of Susan Powell’s said there’s a “huge red flag” in what the husband told police.

Susan Powell, a 28-year-old mother of two young children, was reported missing Dec. 7, when she didn’t show up for work.

Her husband, Josh Powell, has said he went camping with the couple’s boys, ages 2 and 4, in subfreezing temperatures about 12:30 a.m. on Dec. 7 and returned in the evening.

At a press conference Thursday in Puyallup, Wash., Shelby Gifford, a spokeswoman for Susan Powell’s family, said they weren’t surprised authorities named the husband a person of interest “given the events and his reactions to them in the past week.”

“We know that Susan is an excellent mother and would not have tolerated her children being taken out of the home after midnight to go camping in dangerously cold conditions,” Gifford said.

The family also does not believe she took off.

“We have absolutely no reason to believe she would do that,” said Gifford. “The other reason that causes us concern is that if she did make the decision to leave, she would have not gone this long not contacting her family and she would have not left those boys.”

Susan Powell had attended high school in Puyallup, where her father, mother and extended family currently live. The couple met and married in Washington state and moved to the Salt Lake City area approximately five years ago, said Gifford.

While Josh Powell has not been named a suspect in the case, authorities have upgraded Susan Powell’s disapperance to a criminal probe and say Josh Powell’s “lack of cooperation” has made them increasingly suspicious of him.

“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.

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. But he has been uncooperative in providing any details that might explain what happened to his wife, Black said.

“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.

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.

Kirk Graves, the husband of Josh Powell’s sister, told NBC’s “Today” show Thursday that his brother-in-law could be controlling, and was an “interesting person” with a “different” personality.

Asked whether he thought his brother-in-law had something to do with Susan Powell’s disappearance, Graves said he’s avoided analyzing the question.

“Too many emotions, too many family members. I just pray no,” he said.

At Thursday’s press conference, the Susan Powell family in Puyallup said they had no reason to believe her life was endangered.

“If we felt Susan was in danger, we as a family would have taken the appropriate steps to take her out of that situation,” said Gifford. “So some of the things you’re learning this week, we’re learning right along with you.”

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.

Josh Powell on Tuesday did provide a DNA sample to police, 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.

Despite the ongoing investigation, the couple’s two boys are staying with their father and his relatives in Utah.

Susan’s father said he believes his grandchildren are safe, despite the fact Josh is a “person of interest.”

“He’s always been a super father to them,” said Chuck Cox.

Susan’s family is planning a candlelight vigil in her honor Friday night at 7pm in Puyallup. The exact location of the vigil has not been determined.