The father of a missing Oregon mother said she "probably went for a walk" after leaving her home to run errands, a day after detectives discovered she had purchased trail mix, Gatorade and non-lethal sleeping pills at a pharmacy shortly before her disappearance.
Bill Turner, Jennifer Huston's father and a former homicide investigator, declined to say whether he thought foul play was suspected and said the 38-year-old mother of two may have taken a walk somewhere before she vanished nearly a week ago.
"She probably went for a walk," Turner told Fox News on Wednesday. "And she's unable to come home at this point in time."
"I don't want to even go there," he said, when asked about the possibility of foul play.
Huston, of Dundee, Ore., left her home around 5:45 p.m. on Thursday to run errands, according to her husband. Detectives say she withdrew a small sum of money from an ATM before purchasing items at a pharmacy and then filling her 1999 dark green Lexus LX 470 up with gas. She has not been seen or heard from since.
Huston's husband, Kallen, who passed a polygraph test, said his wife had complained of a headache for "several days" prior to her disappearance.
Detectives released new images Tuesday night of Huston, a stay-at-home mom, entering a Rite Aid drug store about 3 miles from her home. She used the cash she had just withdrawn from the Oregon First Community Credit Union in Newberg to purchase items, which included over-the-counter sleeping pills. Police said the amount of sleeping pills she purchased would not be enough for a lethal dose.
Kallen Huston said earlier this week that his wife might have driven off the road and urged motorists to look for any signs of his wife and her vehicle.
"I have a feeling maybe she's in a ditch somewhere," he said. "We've exercised every option that we can think of right now."
Turner told FoxNews.com that authorities are poring over security footage taken from several businesses along a Portland-area highway for any clues into Huston's disappearance.
"A number of businesses up and down the highway have video that captures what happens on the road," Turner said. "They're looking for directional information."
The gas station security footage shows Huston purchasing gas between 6:10 and 6:22 p.m. on Thursday. Turner said he reviewed the footage with police and that it did not show anyone inside the vehicle with his daughter.
"There was nobody in the passenger's seat," Turner said. "We went through all the different camera angles and there was also no movement in the backseat."
Capt. Jeff Kosmicki of the Newberg-Dundee Police Department confirmed that no one is seen inside the vehicle with Jennifer, but noted the footage "is not the best quality."
"She just handed her debit card over and the attendant pumped the gas for her," Kosmicki said of Huston, who has two sons, ages 3 and 6.
Kosmicki said that about 20 to 25 minutes after Huston left the gas station her cell phone "stopped sending any information to the cell tower."
"I don't know if the phone was turned off or if it ran out of battery," he said.
Kosmicki also said surveillance video taken from the bank showed Jennifer withdrawing cash from an ATM just before 6 p.m.
"It's a much better video. You can clearly see her facial details," he said. "Based on her actions, she seemed pretty calm." He said the video showed her opening the door slightly to finish her transaction.
Turner, who once worked with the U.S. Army's Criminal Investigation Command investigating murders and suicides, described his son-in-law as "solid as a rock."
"He and Jennifer met through mutual friends. The best description I have of their relationship is two old souls," Turner told FoxNews.com. "Kallen is the most incredibly patient person I know. They get along. There's no discord in the home whatsoever.
No activity has been recorded on Huston's bank cards, according to police. Authorities said an aerial search conducted Sunday in Yamhill County turned up no trace of this young mother. Kosmicki noted that Huston's vehicle did not have a tracking device.
A Facebook page set up in the search for Huston says she was last seen wearing black and pink Nike shoes and black yoga pants. Her vehicle, a 1999 Lexus LX 470, has an Oregon license plate of WXH 011.
Anyone with information is urged to call the Newberg-Dundee Police Department at 503-538-8321.
FoxNews.com's Cristina Corbin contributed to this report.