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A missing Oregon mom's father, who is a former homicide investigator, told FoxNews.com he is helping police piece together the final moments before his daughter vanished, and described his son-in-law as "solid as a rock."

Investigators are poring over security footage from businesses along a Portland, Ore., highway Monday for any clues into the disappearance of 38-year-old Jennifer Huston, who was last seen four days ago buying gas, her father, Bill Turner, told FoxNews.com.

Turner said authorities have seized video from several businesses near the Circle K gas station in Newburg, where his daughter filled up her 15-year-old SUV on Thursday.

"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."

An intense search is underway for Huston, a stay-at-home mother of two, who was seen on security footage between 6:10 and 6:22 p.m. on Thursday buying gas with her debit card. Her father, a former criminal investigator, 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. "Went through all the different camera angles and there was also no movement in the backseat."

Huston had told her husband she was "running errands," but the debit purchase at Circle K gas station -- a 9-minute drive from her home -- was the only one made on Thursday, according to her father, who said he reviewed her bank records.

"This is not like her," he said. "She’s a highly devoted mom to her boys."

The woman's husband, Kallen Huston, could not be reached by phone early Monday but told local media outlets over the weekend that his wife's disappearance is "completely out of character."

In an interview with KPTV, he spoke directly to his wife, saying, "I love you so much and I miss you ... Please come home."

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.

Huston has not contacted her family and no activity has been recorded on her credit card, her father said. Her cellphone has been off since Thursday. Turner said an aerial search conducted Sunday in Yamhill County turned up no trace of his daughter.

The family is canvassing the neighborhood and highways with Jennifer Huston’s picture, hoping someone will come forward with a tip. Huston has two sons, ages 3 and 6.

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 Dundee police department at 503-538-8321.