"It's still a missing person case. It's highly suspicious," McLachlan said Friday. "We are putting practically every detective we have on this case."
Powell was reported missing on Monday. Detectives in the Salt Lake City suburb interviewed Powell's husband, Josh, who said he had taken the couple's two young children, ages 2 and 4, camping in Utah's west desert despite temperatures that dipped into the teens over the weekend.
Josh Powell returned Monday night, after police had already received a call from relatives who had not heard from the Powell family.
McLachlan said detectives tried to verify Josh Powell's story, but couldn't because snow had covered the spot along The Pony Express Trail where Powell said he took the children.
Josh Powell did not return a call from The Associated Press on Friday.
Susan Powell's family in Puyallup, Wash., south of Seattle, was getting daily updates from police and hoped something would turn up to lead detectives to the missing mother of two.
"This is a really difficult time for the family," said Shelby Gifford, a friend who the family asked to act as a spokeswoman. "They've been really comforted by all of the support. That's something to hang on to right now, and they're very grateful for that."
Gifford said the family has also been in frequent contact with Mrs. Powell's friends, who held a candlelight vigil Thursday night at a park near the Powells' home.
"That's one of the only things that keeps you going," Gifford said. "That and the belief we need to find Susan and we need to find her now."
Gifford said police told the family that Mrs. Powell's purse and cell phone were in the home when it was searched.
The family called police Monday, when she didn't show up for her stockbroker's job at Wells Fargo Financial.
McLachlan said she hasn't contacted anyone since her disappearance. Her parents say she wouldn't have left her two young sons and husband on her own accord.