Investigators returned to Carson City on Sunday with a truck they hope will hold clues to the disappearance of a mother of three.
Undersheriff Steve Albertson and two detectives left Utah after their questioning of Juan Carlos Tellez, 36, provided no answers in their search for Bertha Anguiano, said Chief Deputy Steve Schuette.
They had hoped Tellez could shed light on Anguiano's Nov. 10 disappearance.
Schuette said a forensic examination of the truck will begin Monday. Investigators are seeking evidence that Anguiano may have been in the truck.
Tellez and Joaquin Barcelano, 37, were arrested on Thursday in Salt Lake City after a Utah State Trooper spotted the truck parked at an apartment complex.
Tellez and Barcelo were leaving in another vehicle when Salt Lake deputies stopped them.
Tellez allegedly leapt from the vehicle and pointed a loaded handgun at officers, who then rammed him with their car, said Salt Lake Police Detective Kevin Joiner. Both men were being held without bail in the Salt Lake County jail on charges of aggravated assault.
Anguiano, 33, a married mother of three sons, was last seen in the parking lot of Empire Elementary School talking with an unidentified man on Nov. 10.
Some 90 minutes later, her son Andrew, 3, who was with her at the time, was found abandoned and bloodied at a store in Dayton about 12 miles from the family's home.
The boy told police that he and his mother had been pushed from a truck, and that his mother had been "hit with a stick" and killed.
Schuette said Salt Lake detectives will continue to question Tellez.
"Utah investigators are going to continue this case from their end, that's going to help us from our end," Schuette said.
Tellez has denied having any knowledge of Anguiano or her whereabouts, Sheriff Kenny Furlong said.
The two were believed to have been having an affair, which was a point of contention between Anguiano and her husband, Furlong said.
"Obviously, this investigation will continue indefinitely until we can close it one way or another," Schuette said.