After deliberating for 10 days, jurors found David Westerfield guilty on all counts in the kidnapping and murder of Danielle Van Dam.
The 50-year-old Westerfield showed no emotion as the guilty verdict was read.
He may now face the death penalty. Westerfield was also convicted of misdemeanor possession of child pornography, which prosecutors said pointed to a motive for the abduction.
The jury will return Aug. 28 to begin the penalty phase of the case.